From b164e9a95ff16710bab19890c18aba59a7fb3036 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:21:16 +0200
Subject: [PATCH 01/25] Migrate Lingo config to Strata memory policy

---
 src/Lingo.h | 18 +++++++++++++++---
 1 file changed, 15 insertions(+), 3 deletions(-)

diff --git a/src/Lingo.h b/src/Lingo.h
index 0cba137..6af29c0 100644
--- a/src/Lingo.h
+++ b/src/Lingo.h
@@ -1,5 +1,7 @@
 #pragma once
 
+#include <Strata.h>
+
 #include <array>
 #include <atomic>
 #include <cstddef>
@@ -96,10 +98,20 @@ class LingoLanguage {
 };
 
 struct LingoConfig {
+	Strata::MemoryPolicy memory{
+	    .allocation = Strata::Placement::PreferExternal,
+	    .taskStack = Strata::Placement::Internal,
+	};
 	LingoLanguage defaultLanguage{};
 	size_t maxTables = 64;
 	const char *missingTranslation = "";
-	bool preferPsram = true;
+};
+
+struct LingoDiag {
+	size_t tableCount = 0;
+	size_t tableCapacity = 0;
+	Strata::Placement registryPlacement = Strata::Placement::PreferExternal;
+	Strata::Region registryRegion = Strata::Region::Unknown;
 };
 
 template <typename TKey> class LingoEntry {
@@ -251,7 +263,7 @@ class Lingo {
 
 	size_t tableCount() const;
 	size_t tableCapacity() const;
-	bool preferPsram() const;
+	LingoDiag getDiagnostics() const;
 
   private:
 	LingoResult addTableRaw(
@@ -269,7 +281,7 @@ class Lingo {
 	size_t _tableCount = 0;
 	size_t _tableCapacity = 0;
 	const char *_missingTranslation = "";
-	bool _preferPsram = true;
+	Strata::Placement _registryPlacement = Strata::Placement::PreferExternal;
 	bool _initialized = false;
 	std::atomic<uint16_t> _defaultLanguage{0};
 };

From 1c86b71497616fe5539d8f0cc5de2fb069f9c8d5 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:21:43 +0200
Subject: [PATCH 02/25] Route Lingo registry ownership through Strata

---
 src/Lingo.cpp | 38 +++++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/src/Lingo.cpp b/src/Lingo.cpp
index 7880c50..bd2a2f5 100644
--- a/src/Lingo.cpp
+++ b/src/Lingo.cpp
@@ -1,9 +1,7 @@
 #include "Lingo.h"
 
-#include "internal/LingoMemory.h"
-
 #include <limits>
-#include <new>
+#include <memory>
 
 namespace lingo_internal {
 
@@ -34,7 +32,10 @@ LingoResult Lingo::init(const LingoConfig &config) {
 		);
 	}
 
-	if (config.maxTables == 0 || config.missingTranslation == nullptr) {
+	if (
+		config.maxTables == 0 ||
+		config.missingTranslation == nullptr ||
+		!Strata::validMemoryPolicy(config.memory)) {
 		return LingoResult::failure(LingoStatus::InvalidConfig, "invalid lingo configuration");
 	}
 
@@ -46,24 +47,26 @@ LingoResult Lingo::init(const LingoConfig &config) {
 		);
 	}
 
-	const size_t allocationSize = sizeof(lingo_internal::LingoRegisteredTable) * config.maxTables;
-	void *memory = lingo_internal::allocate(allocationSize, config.preferPsram);
-	if (memory == nullptr) {
+	auto *tables = Strata::allocateArray<lingo_internal::LingoRegisteredTable>(
+	    config.maxTables,
+	    config.memory.allocation
+	);
+	if (tables == nullptr) {
 		return LingoResult::failure(
 		    LingoStatus::AllocationFailed,
 		    "translation table registry allocation failed"
 		);
 	}
 
-	_tables = static_cast<lingo_internal::LingoRegisteredTable *>(memory);
 	for (size_t index = 0; index < config.maxTables; ++index) {
-		new (&_tables[index]) lingo_internal::LingoRegisteredTable();
+		std::construct_at(&tables[index]);
 	}
 
+	_tables = tables;
 	_tableCount = 0;
 	_tableCapacity = config.maxTables;
 	_missingTranslation = config.missingTranslation;
-	_preferPsram = config.preferPsram;
+	_registryPlacement = config.memory.allocation;
 	_defaultLanguage.store(config.defaultLanguage.value(), std::memory_order_release);
 	_initialized = true;
 
@@ -76,15 +79,15 @@ LingoResult Lingo::end() {
 	}
 
 	for (size_t index = 0; index < _tableCapacity; ++index) {
-		_tables[index].~LingoRegisteredTable();
+		std::destroy_at(&_tables[index]);
 	}
 
-	lingo_internal::release(_tables);
+	Strata::free(_tables);
 	_tables = nullptr;
 	_tableCount = 0;
 	_tableCapacity = 0;
 	_missingTranslation = kEmptyTranslation;
-	_preferPsram = true;
+	_registryPlacement = Strata::Placement::PreferExternal;
 	_defaultLanguage.store(0, std::memory_order_release);
 	_initialized = false;
 
@@ -218,6 +221,11 @@ size_t Lingo::tableCapacity() const {
 	return _tableCapacity;
 }
 
-bool Lingo::preferPsram() const {
-	return _preferPsram;
+LingoDiag Lingo::getDiagnostics() const {
+	return LingoDiag{
+	    .tableCount = _tableCount,
+	    .tableCapacity = _tableCapacity,
+	    .registryPlacement = _registryPlacement,
+	    .registryRegion = _tables == nullptr ? Strata::Region::Unknown : Strata::regionOf(_tables),
+	};
 }

From 231187854ab7a523ed0d46b365956799aff881cc Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:22:32 +0200
Subject: [PATCH 03/25] Update Lingo host tests for Strata diagnostics

---
 tests/host/lingo_host_tests.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/tests/host/lingo_host_tests.cpp b/tests/host/lingo_host_tests.cpp
index 9f6d8b5..b79b3e7 100644
--- a/tests/host/lingo_host_tests.cpp
+++ b/tests/host/lingo_host_tests.cpp
@@ -76,16 +76,20 @@ void testLifecycle() {
 	config.defaultLanguage = Language::Hu;
 	config.maxTables = 8;
 	config.missingTranslation = "<missing>";
-	config.preferPsram = true;
+	config.memory.allocation = Strata::Placement::PreferExternal;
 
 	assert(lingo.init(config));
 	assert(lingo.initialized());
 	assert(lingo.tableCapacity() == 8);
-	assert(lingo.preferPsram());
+	const LingoDiag diag = lingo.getDiagnostics();
+	assert(diag.tableCount == 0);
+	assert(diag.tableCapacity == 8);
+	assert(diag.registryPlacement == Strata::Placement::PreferExternal);
 	assert(!lingo.init(config));
 
 	assert(lingo.end());
 	assert(!lingo.initialized());
+	assert(lingo.getDiagnostics().registryRegion == Strata::Region::Unknown);
 	assert(lingo.end());
 
 	assert(lingo.init(config));
@@ -107,6 +111,7 @@ void testRegistrationAndDomainIsolation() {
 	assert(lingo.addTable(Language::En, TIME_EN));
 
 	assert(lingo.tableCount() == 6);
+	assert(lingo.getDiagnostics().tableCount == 6);
 
 	assert(std::strcmp(lingo.get(CommonKey::Save), "Mentés") == 0);
 	assert(std::strcmp(lingo.get(SoftwareKey::Save), "Mentés") == 0);

From ae7fd91ab1acd7fac9c553a3ed9b26d68fb2dbb0 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:22:52 +0200
Subject: [PATCH 04/25] Add Strata memory policy tests

---
 tests/host/memory_policy_tests.cpp | 99 ++++++++++++++++++++++++++++++
 1 file changed, 99 insertions(+)
 create mode 100644 tests/host/memory_policy_tests.cpp

diff --git a/tests/host/memory_policy_tests.cpp b/tests/host/memory_policy_tests.cpp
new file mode 100644
index 0000000..8e18250
--- /dev/null
+++ b/tests/host/memory_policy_tests.cpp
@@ -0,0 +1,99 @@
+#include <Lingo.h>
+
+#include <cassert>
+#include <iostream>
+
+enum class Language : uint16_t {
+	En,
+};
+
+void testDefaultPreservesExternalPreference() {
+	LingoConfig config;
+	assert(config.memory.allocation == Strata::Placement::PreferExternal);
+	assert(config.memory.taskStack == Strata::Placement::Internal);
+
+	Lingo lingo;
+	config.defaultLanguage = Language::En;
+	assert(lingo.init(config));
+
+	const LingoDiag diag = lingo.getDiagnostics();
+	assert(diag.registryPlacement == Strata::Placement::PreferExternal);
+	assert(diag.registryRegion == Strata::Region::Unknown);
+}
+
+void testExplicitInternalPlacement() {
+	Lingo lingo;
+	LingoConfig config;
+	config.defaultLanguage = Language::En;
+	config.memory.allocation = Strata::Placement::Internal;
+
+	assert(lingo.init(config));
+	assert(lingo.getDiagnostics().registryPlacement == Strata::Placement::Internal);
+}
+
+void testExplicitBackendDefaultPlacement() {
+	Lingo lingo;
+	LingoConfig config;
+	config.defaultLanguage = Language::En;
+	config.memory.allocation = Strata::Placement::Default;
+
+	assert(lingo.init(config));
+	assert(lingo.getDiagnostics().registryPlacement == Strata::Placement::Default);
+}
+
+void testRequiredExternalFailsWithoutExternalMemory() {
+	Lingo lingo;
+	LingoConfig config;
+	config.defaultLanguage = Language::En;
+	config.memory.allocation = Strata::Placement::RequireExternal;
+
+	const LingoResult result = lingo.init(config);
+	assert(!result);
+	assert(result.status == LingoStatus::AllocationFailed);
+	assert(!lingo.initialized());
+}
+
+void testInvalidMemoryPolicyRejected() {
+	Lingo lingo;
+	LingoConfig config;
+	config.defaultLanguage = Language::En;
+	config.memory.allocation = static_cast<Strata::Placement>(0xff);
+
+	const LingoResult allocationResult = lingo.init(config);
+	assert(!allocationResult);
+	assert(allocationResult.status == LingoStatus::InvalidConfig);
+
+	config.memory.allocation = Strata::Placement::PreferExternal;
+	config.memory.taskStack = static_cast<Strata::Placement>(0xff);
+	const LingoResult stackResult = lingo.init(config);
+	assert(!stackResult);
+	assert(stackResult.status == LingoStatus::InvalidConfig);
+}
+
+void testEndResetsRegistryDiagnostics() {
+	Lingo lingo;
+	LingoConfig config;
+	config.defaultLanguage = Language::En;
+	config.memory.allocation = Strata::Placement::Internal;
+
+	assert(lingo.init(config));
+	assert(lingo.end());
+
+	const LingoDiag diag = lingo.getDiagnostics();
+	assert(diag.tableCount == 0);
+	assert(diag.tableCapacity == 0);
+	assert(diag.registryPlacement == Strata::Placement::PreferExternal);
+	assert(diag.registryRegion == Strata::Region::Unknown);
+}
+
+int main() {
+	testDefaultPreservesExternalPreference();
+	testExplicitInternalPlacement();
+	testExplicitBackendDefaultPlacement();
+	testRequiredExternalFailsWithoutExternalMemory();
+	testInvalidMemoryPolicyRejected();
+	testEndResetsRegistryDiagnostics();
+
+	std::cout << "Lingo Strata memory policy tests passed\n";
+	return 0;
+}

From c6f6af79aa45aa76f162ce5ed42d0dc8c01a3593 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:23:01 +0200
Subject: [PATCH 05/25] Remove bespoke PSRAM allocation tests

---
 tests/host/psram_allocation_tests.cpp | 77 ---------------------------
 1 file changed, 77 deletions(-)
 delete mode 100644 tests/host/psram_allocation_tests.cpp

diff --git a/tests/host/psram_allocation_tests.cpp b/tests/host/psram_allocation_tests.cpp
deleted file mode 100644
index c1f645d..0000000
--- a/tests/host/psram_allocation_tests.cpp
+++ /dev/null
@@ -1,77 +0,0 @@
-#include <Lingo.h>
-
-#include <esp_heap_caps.h>
-
-#include <cassert>
-#include <iostream>
-
-enum class Language : uint16_t {
-	En,
-};
-
-void testPsramPreferredWhenAvailable() {
-	lingo_psram_test::reset();
-	lingo_psram_test::spiramTotal = 1024 * 1024;
-
-	Lingo lingo;
-	LingoConfig config;
-	config.defaultLanguage = Language::En;
-	config.preferPsram = true;
-
-	assert(lingo.init(config));
-	assert(lingo_psram_test::spiramAllocations == 1);
-	assert(lingo_psram_test::internalAllocations == 0);
-}
-
-void testInternalHeapFallbackWhenPsramAllocationFails() {
-	lingo_psram_test::reset();
-	lingo_psram_test::spiramTotal = 1024 * 1024;
-	lingo_psram_test::failSpiramAllocation = true;
-
-	Lingo lingo;
-	LingoConfig config;
-	config.defaultLanguage = Language::En;
-	config.preferPsram = true;
-
-	assert(lingo.init(config));
-	assert(lingo_psram_test::spiramAllocations == 1);
-	assert(lingo_psram_test::internalAllocations == 1);
-}
-
-void testInternalHeapWhenPsramUnavailable() {
-	lingo_psram_test::reset();
-	lingo_psram_test::spiramTotal = 0;
-
-	Lingo lingo;
-	LingoConfig config;
-	config.defaultLanguage = Language::En;
-	config.preferPsram = true;
-
-	assert(lingo.init(config));
-	assert(lingo_psram_test::spiramAllocations == 0);
-	assert(lingo_psram_test::internalAllocations == 1);
-}
-
-void testInternalHeapWhenPsramPreferenceDisabled() {
-	lingo_psram_test::reset();
-	lingo_psram_test::spiramTotal = 1024 * 1024;
-
-	Lingo lingo;
-	LingoConfig config;
-	config.defaultLanguage = Language::En;
-	config.preferPsram = false;
-
-	assert(lingo.init(config));
-	assert(lingo_psram_test::spiramAllocations == 0);
-	assert(lingo_psram_test::internalAllocations == 1);
-}
-
-int main() {
-	testPsramPreferredWhenAvailable();
-	testInternalHeapFallbackWhenPsramAllocationFails();
-	testInternalHeapWhenPsramUnavailable();
-	testInternalHeapWhenPsramPreferenceDisabled();
-
-	std::cout << "Lingo PSRAM allocation tests passed\n";
-	return 0;
-}

From 9de445183074f6a1f4c692761b2721dfe2cb8cd4 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:23:08 +0200
Subject: [PATCH 06/25] Remove Lingo ESP heap allocation stub

---
 tests/host/esp_stubs/esp_heap_caps.h | 47 ----------------------------
 1 file changed, 47 deletions(-)
 delete mode 100644 tests/host/esp_stubs/esp_heap_caps.h

diff --git a/tests/host/esp_stubs/esp_heap_caps.h b/tests/host/esp_stubs/esp_heap_caps.h
deleted file mode 100644
index 32f6d3c..0000000
--- a/tests/host/esp_stubs/esp_heap_caps.h
+++ /dev/null
@@ -1,47 +0,0 @@
-#pragma once
-
-#include <cstddef>
-#include <cstdlib>
-
-#define MALLOC_CAP_SPIRAM 0x1
-#define MALLOC_CAP_8BIT 0x2
-
-namespace lingo_psram_test {
-
-inline std::size_t spiramTotal = 0;
-inline bool failSpiramAllocation = false;
-inline std::size_t spiramAllocations = 0;
-inline std::size_t internalAllocations = 0;
-
-inline void reset() {
-	spiramTotal = 0;
-	failSpiramAllocation = false;
-	spiramAllocations = 0;
-	internalAllocations = 0;
-}
-
-} // namespace lingo_psram_test
-
-inline std::size_t heap_caps_get_total_size(int caps) {
-	if ((caps & MALLOC_CAP_SPIRAM) != 0) {
-		return lingo_psram_test::spiramTotal;
-	}
-	return 0;
-}
-
-inline void *heap_caps_malloc(std::size_t size, int caps) {
-	if ((caps & MALLOC_CAP_SPIRAM) != 0) {
-		++lingo_psram_test::spiramAllocations;
-		if (lingo_psram_test::failSpiramAllocation) {
-			return nullptr;
-		}
-		return std::malloc(size);
-	}
-
-	++lingo_psram_test::internalAllocations;
-	return std::malloc(size);
-}
-
-inline void heap_caps_free(void *ptr) {
-	std::free(ptr);
-}

From 4ea9c4974ab2d33c0f2df385fc78807765741c77 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:23:15 +0200
Subject: [PATCH 07/25] Remove bespoke Lingo allocator

---
 src/internal/LingoMemory.h | 44 --------------------------------------
 1 file changed, 44 deletions(-)
 delete mode 100644 src/internal/LingoMemory.h

diff --git a/src/internal/LingoMemory.h b/src/internal/LingoMemory.h
deleted file mode 100644
index 71f3b96..0000000
--- a/src/internal/LingoMemory.h
+++ /dev/null
@@ -1,44 +0,0 @@
-#pragma once
-
-#include <cstddef>
-#include <cstdlib>
-
-#if defined(ESP32)
-#include <esp_heap_caps.h>
-#endif
-
-namespace lingo_internal {
-
-inline void *allocate(size_t size, bool preferPsram) {
-	if (size == 0) {
-		return nullptr;
-	}
-
-#if defined(ESP32)
-	if (preferPsram && heap_caps_get_total_size(MALLOC_CAP_SPIRAM) > 0) {
-		void *ptr = heap_caps_malloc(size, MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT);
-		if (ptr != nullptr) {
-			return ptr;
-		}
-	}
-
-	return heap_caps_malloc(size, MALLOC_CAP_8BIT);
-#else
-	(void)preferPsram;
-	return std::malloc(size);
-#endif
-}
-
-inline void release(void *ptr) {
-	if (ptr == nullptr) {
-		return;
-	}
-
-#if defined(ESP32)
-	heap_caps_free(ptr);
-#else
-	std::free(ptr);
-#endif
-}
-
-} // namespace lingo_internal

From 4d9aa0fadde134e12f40b49a4a9899f533d53bbd Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:23:52 +0200
Subject: [PATCH 08/25] Add Strata v0.1.2 dependency for Lingo v0.2.0

---
 library.json | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/library.json b/library.json
index 8022ede..c2a46a9 100644
--- a/library.json
+++ b/library.json
@@ -1,12 +1,13 @@
 {
   "name": "Lingo",
-  "version": "0.1.0",
-  "description": "Strongly typed, feature-oriented translations for ESP32 with PSRAM-first registry allocation.",
+  "version": "0.2.0",
+  "description": "Strongly typed, feature-oriented translations for ESP32 with Strata-backed registry allocation.",
   "keywords": [
     "esp32",
     "translation",
     "localization",
     "i18n",
+    "strata",
     "psram",
     "lingo"
   ],
@@ -23,6 +24,9 @@
   "license": "MIT",
   "frameworks": "arduino",
   "platforms": "espressif32",
+  "dependencies": {
+    "Strata": "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/ZekStack/strata.git#v0.1.2"
+  },
   "build": {
     "srcDir": "src",
     "includeDir": "src",

From 88310252be856e89d761afb96541102d677c24e3 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:24:02 +0200
Subject: [PATCH 09/25] Bump Lingo metadata to v0.2.0

---
 library.properties | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/library.properties b/library.properties
index be87c7f..48690bd 100644
--- a/library.properties
+++ b/library.properties
@@ -1,9 +1,9 @@
 name=Lingo
-version=0.1.0
+version=0.2.0
 author=zekageri
 maintainer=zekageri
 sentence=Strongly typed, feature-oriented translations for ESP32.
-paragraph=Provides isolated enum-key translation domains, multiple feature tables per language, allocation-free lookup, same-domain fallback, and PSRAM-first registry allocation.
+paragraph=Provides isolated enum-key translation domains, multiple feature tables per language, allocation-free lookup, same-domain fallback, and Strata-backed registry allocation.
 category=Data Processing
 url=https://github.com/ZekStack/lingo
 repository=https://github.com/ZekStack/lingo.git

From ccf0be55136a69345bbd31877c83ae9c975d4a43 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:24:49 +0200
Subject: [PATCH 10/25] Align Lingo CI with Strata memory ownership

---
 .github/workflows/ci.yml | 97 ++++++++++++++++++++++++++++++++++++----
 1 file changed, 88 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 32a6cb5..abde632 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -12,9 +12,14 @@ concurrency:
   cancel-in-progress: false
 
 env:
+  ARDUINO_BOARD_MANAGER_ADDITIONAL_URLS: https://espressif.github.io/arduino-esp32/package_esp32_index.json
+  ARDUINO_CLI_VERSION: 1.5.0
+  ARDUINO_NETWORK_CONNECTION_TIMEOUT: 240s
+  ESP32_CORE_VERSION: 3.3.9
   PIOARDUINO_PLATFORM_URL: https://github.com/pioarduino/platform-espressif32/releases/download/55.03.39/platform-espressif32.zip
   PIOARDUINO_PLATFORM_VERSION: 55.03.39
   PIOARDUINO_VERSION: 6.1.19
+  STRATA_VERSION: v0.1.2
 
 jobs:
   metadata:
@@ -42,6 +47,7 @@ jobs:
       - uses: actions/checkout@v4
       - name: Audit embedded boundaries
         run: |
+          set -e
           if grep -RInE '#include[[:space:]]+[<"](Accord|Curier|Flow|Fresh|Link|Phase|Pulse|Seal|Signal|Tempo|Trace|Worker)\.h[>"]' src; then
             echo "Lingo must not depend on another ZekStack library"
             exit 1
@@ -62,32 +68,47 @@ jobs:
             echo "Lingo internals must not use Arduino String"
             exit 1
           fi
+          if grep -RInE 'heap_caps_|MALLOC_CAP_|ps_malloc|#include[[:space:]]+[<"]esp_heap_caps\.h[>"]|(^|[^[:alnum:]_:])malloc[[:space:]]*\(|(^|[^[:alnum:]_:])calloc[[:space:]]*\(|(^|[^[:alnum:]_:])realloc[[:space:]]*\(|(^|[^[:alnum:]_:])free[[:space:]]*\(|(^|[^[:alnum:]_])new[[:space:](]|(^|[^[:alnum:]_])delete[[:space:](]' src; then
+            echo "Lingo-owned allocations must route through Strata"
+            exit 1
+          fi
 
   host-tests:
     runs-on: [self-hosted, zekstack-ci]
     needs: source-audit
     steps:
       - uses: actions/checkout@v4
+      - name: Checkout Strata
+        run: |
+          rm -rf /tmp/lingo-strata
+          git clone --depth 1 --branch "${STRATA_VERSION}" \
+            https://github.com/ZekStack/strata.git /tmp/lingo-strata
       - name: Build host behavior tests
         run: |
           g++ -std=c++20 -Wall -Wextra -pedantic \
             -Isrc \
+            -I/tmp/lingo-strata/src \
             src/Lingo.cpp \
+            /tmp/lingo-strata/src/strata/Allocation.cpp \
+            /tmp/lingo-strata/src/strata/Diagnostics.cpp \
+            /tmp/lingo-strata/src/strata/internal/PlatformGeneric.cpp \
             tests/host/lingo_host_tests.cpp \
             -o /tmp/lingo-host-tests
       - name: Run host behavior tests
         run: /tmp/lingo-host-tests
-      - name: Build PSRAM allocation tests
+      - name: Build memory policy tests
         run: |
           g++ -std=c++20 -Wall -Wextra -pedantic \
-            -DESP32 \
-            -Itests/host/esp_stubs \
             -Isrc \
+            -I/tmp/lingo-strata/src \
             src/Lingo.cpp \
-            tests/host/psram_allocation_tests.cpp \
-            -o /tmp/lingo-psram-tests
-      - name: Run PSRAM allocation tests
-        run: /tmp/lingo-psram-tests
+            /tmp/lingo-strata/src/strata/Allocation.cpp \
+            /tmp/lingo-strata/src/strata/Diagnostics.cpp \
+            /tmp/lingo-strata/src/strata/internal/PlatformGeneric.cpp \
+            tests/host/memory_policy_tests.cpp \
+            -o /tmp/lingo-memory-policy-tests
+      - name: Run memory policy tests
+        run: /tmp/lingo-memory-policy-tests
 
   build-examples:
     runs-on: [self-hosted, zekstack-ci]
@@ -112,6 +133,8 @@ jobs:
             ~/.platformio
             ~/.cache/pip
           key: ${{ runner.os }}-pioarduino-${{ env.PIOARDUINO_VERSION }}-${{ env.PIOARDUINO_PLATFORM_VERSION }}-${{ hashFiles('**/library.json') }}
+          restore-keys: |
+            ${{ runner.os }}-pioarduino-${{ env.PIOARDUINO_VERSION }}-${{ env.PIOARDUINO_PLATFORM_VERSION }}-
       - name: Install PIOArduino
         run: |
           python -m pip install --upgrade "pioarduino==${PIOARDUINO_VERSION}"
@@ -124,13 +147,69 @@ jobs:
               --board "${{ matrix.board }}" \
               --lib="." \
               --project-option "platform=${PIOARDUINO_PLATFORM_URL}" \
+              --project-option "lib_deps=https://github.com/ZekStack/strata.git#${STRATA_VERSION}" \
               --project-option "build_unflags=-std=gnu++11" \
               --project-option "build_flags=-std=gnu++20"
           done
 
+  arduino-cli:
+    runs-on: [self-hosted, zekstack-ci]
+    needs: source-audit
+    strategy:
+      fail-fast: false
+      matrix:
+        board:
+          - fqbn: esp32:esp32:esp32
+            name: esp32dev
+          - fqbn: esp32:esp32:esp32s3
+            name: esp32-s3-devkitc-1
+          - fqbn: esp32:esp32:esp32c3
+            name: esp32-c3-devkitm-1
+          - fqbn: esp32:esp32:esp32p4
+            name: esp32-p4-evboard
+    steps:
+      - uses: actions/checkout@v4
+      - uses: arduino/setup-arduino-cli@v2
+        with:
+          version: ${{ env.ARDUINO_CLI_VERSION }}
+      - name: Cache Arduino CLI packages
+        uses: actions/cache@v4
+        with:
+          path: |
+            ~/.arduino15
+            ~/.cache/arduino
+          key: ${{ runner.os }}-arduino-cli-${{ env.ARDUINO_CLI_VERSION }}-esp32-${{ env.ESP32_CORE_VERSION }}
+          restore-keys: |
+            ${{ runner.os }}-arduino-cli-${{ env.ARDUINO_CLI_VERSION }}-esp32-
+      - name: Install ESP32 core
+        run: |
+          arduino-cli core update-index
+          arduino-cli core install "esp32:esp32@${ESP32_CORE_VERSION}"
+      - name: Add local libraries to sketchbook
+        run: |
+          set -e
+          SKETCHBOOK_DIR="${HOME}/Arduino"
+          rm -rf "$SKETCHBOOK_DIR/libraries/Lingo" "$SKETCHBOOK_DIR/libraries/Strata"
+          mkdir -p "$SKETCHBOOK_DIR/libraries/Lingo"
+          rsync -a --delete --exclude ".git" ./ "$SKETCHBOOK_DIR/libraries/Lingo/"
+          git clone --depth 1 --branch "${STRATA_VERSION}" \
+            https://github.com/ZekStack/strata.git \
+            "$SKETCHBOOK_DIR/libraries/Strata"
+      - name: Build examples (${{ matrix.board.name }})
+        env:
+          FQBN: ${{ matrix.board.fqbn }}
+        run: |
+          set -e
+          for sketch in examples/*; do
+            arduino-cli compile \
+              --fqbn "$FQBN" \
+              --build-property "compiler.cpp.extra_flags=-std=gnu++20" \
+              "$sketch"
+          done
+
   release:
     if: startsWith(github.ref, 'refs/tags/v')
-    needs: [metadata, clang-format, source-audit, host-tests, build-examples]
+    needs: [metadata, clang-format, source-audit, host-tests, build-examples, arduino-cli]
     runs-on: [self-hosted, zekstack-ci]
     permissions:
       contents: write
@@ -142,8 +221,8 @@ jobs:
         run: |
           VERSION="${GITHUB_REF_NAME#v}"
           awk -v version="$VERSION" '
+            $0 == "## " {if (capture) exit}
             $0 == "## " version {capture=1; next}
-            capture && /^## / {exit}
             capture {print}
           ' CHANGELOG.md > /tmp/release-notes.md
           gh release create "$GITHUB_REF_NAME" \

From 61880c085058844f9a34604515f1f037868eb0c3 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:25:08 +0200
Subject: [PATCH 11/25] Document Lingo v0.2.0 Strata migration

---
 CHANGELOG.md | 25 +++++++++++++++++++++++++
 1 file changed, 25 insertions(+)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index a4cad5d..f36f0b3 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,31 @@
 
 All notable changes to Lingo are documented in this file.
 
+## 0.2.0
+
+- Add Strata v0.1.2 as Lingo's memory ownership dependency.
+- Replace `LingoConfig::preferPsram` with the shared `Strata::MemoryPolicy` configuration contract.
+- Preserve the v0.1.x default registry behavior with `memory.allocation = Strata::Placement::PreferExternal`.
+- Route the bounded translation-table registry through Strata typed allocation and `Strata::free()`.
+- Add explicit `Default`, `Internal`, `PreferExternal`, and `RequireExternal` placement support.
+- Add `LingoDiag` with requested registry placement and observed registry region.
+- Validate Strata memory policies during `init()` and continue returning `LingoStatus::AllocationFailed` for unsatisfied allocations.
+- Remove the bespoke ESP-IDF heap allocator, PSRAM test stubs, and direct `heap_caps_*` dependency.
+- Add CI source contracts preventing direct heap allocation paths from returning to Lingo-owned code.
+- Add host memory-policy coverage and Arduino CLI builds alongside the existing PlatformIO ESP32 matrix.
+
+### Migration from 0.1.x
+
+```cpp
+// 0.1.x
+config.preferPsram = false;
+
+// 0.2.0
+config.memory.allocation = Strata::Placement::Internal;
+```
+
+The former default `preferPsram = true` maps to `Strata::Placement::PreferExternal` and remains the Lingo default in v0.2.0.
+
 ## 0.1.0
 
 - Add strongly typed enum-key translation domains without RTTI.

From e95e7ee7e1b6c797c9d1da287e45f2d14dc2bf43 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:25:45 +0200
Subject: [PATCH 12/25] Document Lingo Strata API

---
 docs/api.md | 41 ++++++++++++++++++++++++++++++++++++-----
 1 file changed, 36 insertions(+), 5 deletions(-)

diff --git a/docs/api.md b/docs/api.md
index a5f719e..9a3450a 100644
--- a/docs/api.md
+++ b/docs/api.md
@@ -4,14 +4,26 @@
 
 ```cpp
 struct LingoConfig {
+	Strata::MemoryPolicy memory{
+	    .allocation = Strata::Placement::PreferExternal,
+	    .taskStack = Strata::Placement::Internal,
+	};
 	LingoLanguage defaultLanguage{};
 	size_t maxTables = 64;
 	const char *missingTranslation = "";
-	bool preferPsram = true;
 };
 ```
 
-`preferPsram` controls the registry allocation. On ESP32, Lingo first attempts PSRAM and falls back to normal 8-bit capable heap. On host builds it uses normal heap allocation.
+`memory.allocation` controls the one bounded registry allocation owned by Lingo. The default is `Strata::Placement::PreferExternal`, preserving the v0.1.x PSRAM-first behavior with internal-memory fallback.
+
+Lingo does not create tasks, so `memory.taskStack` currently has no runtime storage to control. It remains part of the config to use the same `Strata::MemoryPolicy` contract as other ZekStack libraries. The complete policy is validated by `init()`.
+
+Useful allocation placements are:
+
+- `Strata::Placement::Default` - use Strata's backend-default allocation policy.
+- `Strata::Placement::Internal` - require internal memory.
+- `Strata::Placement::PreferExternal` - prefer external memory and allow safe fallback.
+- `Strata::Placement::RequireExternal` - require external memory; initialization fails if unavailable.
 
 ## `LingoResult`
 
@@ -24,6 +36,8 @@ if (!result) {
 }
 ```
 
+Invalid memory policies return `LingoStatus::InvalidConfig`. An otherwise valid policy that cannot satisfy the registry allocation returns `LingoStatus::AllocationFailed`.
+
 ## Lifecycle
 
 ```cpp
@@ -32,6 +46,8 @@ LingoResult end();
 bool initialized() const;
 ```
 
+`init()` performs Lingo's only owned dynamic allocation. `end()` releases it through Strata. Re-initialization after `end()` is supported.
+
 ## Tables
 
 ```cpp
@@ -42,7 +58,7 @@ LingoResult addTable(
 );
 ```
 
-Only one table may be registered for a given `{language, key enum type}` pair.
+Only one table may be registered for a given `{language, key enum type}` pair. Registration does not allocate.
 
 ## Language selection
 
@@ -75,10 +91,25 @@ const char *find(TKey key, TLanguage language) const;
 
 `get(key, language)` first checks the requested language, then the default language, then returns `missingTranslation`.
 
-## Registry information
+Lookup remains allocation-free.
+
+## Registry information and diagnostics
 
 ```cpp
 size_t tableCount() const;
 size_t tableCapacity() const;
-bool preferPsram() const;
+LingoDiag getDiagnostics() const;
 ```
+
+`LingoDiag` keeps requested policy separate from observed memory location:
+
+```cpp
+struct LingoDiag {
+	size_t tableCount;
+	size_t tableCapacity;
+	Strata::Placement registryPlacement;
+	Strata::Region registryRegion;
+};
+```
+
+For example, `registryPlacement == Strata::Placement::PreferExternal` may legitimately result in `registryRegion == Strata::Region::Internal` when external memory is unavailable and fallback is allowed.

From b864d09eb40fe5053da51b3646086c3453510589 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:26:03 +0200
Subject: [PATCH 13/25] Update Lingo getting started for Strata

---
 docs/getting-started.md | 20 ++++++++++++++++++--
 1 file changed, 18 insertions(+), 2 deletions(-)

diff --git a/docs/getting-started.md b/docs/getting-started.md
index a2b9e9f..af6004c 100644
--- a/docs/getting-started.md
+++ b/docs/getting-started.md
@@ -1,6 +1,6 @@
 # Getting started
 
-Lingo maps strongly typed enum keys to static translation strings.
+Lingo maps strongly typed enum keys to static translation strings and uses Strata for its bounded registry allocation.
 
 ## 1. Define languages
 
@@ -45,7 +45,7 @@ Lingo lingo;
 
 LingoConfig config;
 config.defaultLanguage = Language::Hu;
-config.preferPsram = true;
+config.memory.allocation = Strata::Placement::PreferExternal;
 
 if (!lingo.init(config)) {
 	return;
@@ -55,6 +55,8 @@ lingo.addTable(Language::Hu, SOFTWARE_HU);
 lingo.addTable(Language::En, SOFTWARE_EN);
 ```
 
+`PreferExternal` is already Lingo's default and preserves the v0.1.x PSRAM-first behavior. Set `Internal` when the registry must stay in internal RAM, or `RequireExternal` when initialization must fail instead of falling back.
+
 ## 5. Translate
 
 ```cpp
@@ -64,3 +66,17 @@ const char *english = lingo.get(SoftwareKey::Install, Language::En);
 ```
 
 `get()` never returns `nullptr`. Use `find()` when the caller needs a strict nullable lookup.
+
+## 6. Inspect registry placement
+
+```cpp
+const LingoDiag diag = lingo.getDiagnostics();
+
+// Requested policy.
+Strata::Placement requested = diag.registryPlacement;
+
+// Actual memory region, when the platform can identify it.
+Strata::Region actual = diag.registryRegion;
+```
+
+Requested placement and observed region are intentionally separate because `PreferExternal` may fall back to internal memory.

From 03207926486344e1cf49e6edffca1cbd13493dfc Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:26:16 +0200
Subject: [PATCH 14/25] Replace Lingo PSRAM config docs with Strata policy

---
 docs/configuration.md | 42 +++++++++++++++++++++++++++++++++++++-----
 1 file changed, 37 insertions(+), 5 deletions(-)

diff --git a/docs/configuration.md b/docs/configuration.md
index 3edf270..a87d43b 100644
--- a/docs/configuration.md
+++ b/docs/configuration.md
@@ -1,5 +1,27 @@
 # Configuration
 
+## `memory`
+
+Lingo uses the shared ZekStack `Strata::MemoryPolicy` configuration contract.
+
+```cpp
+LingoConfig config;
+config.memory.allocation = Strata::Placement::PreferExternal;
+```
+
+Lingo owns one bounded dynamic allocation: the translation-table registry created by `init()`. `memory.allocation` controls that registry.
+
+The default is `Strata::Placement::PreferExternal`, which preserves the v0.1.x behavior: prefer external memory and allow safe fallback to internal memory.
+
+Available placements are:
+
+- `Strata::Placement::Default` - use the Strata backend's default allocation policy.
+- `Strata::Placement::Internal` - allocate the registry from internal memory.
+- `Strata::Placement::PreferExternal` - prefer external memory and allow fallback.
+- `Strata::Placement::RequireExternal` - require external memory; `init()` returns `LingoStatus::AllocationFailed` when it cannot be satisfied.
+
+Lingo does not own any tasks, so `memory.taskStack` currently controls no Lingo allocation. It remains part of the config for ecosystem consistency and the full memory policy is validated by `init()`.
+
 ## `defaultLanguage`
 
 The default language is stored during `init()`. It does not need to have a table registered yet, which allows normal boot-time initialization before features register their translations.
@@ -18,7 +40,7 @@ Use `setDefaultLanguage()` after registration to change the selected language at
 config.maxTables = 64;
 ```
 
-Lingo allocates the registry once during `init()`. Table registration and translation lookup do not allocate.
+Lingo allocates the complete registry once during `init()`. Table registration and translation lookup do not allocate.
 
 For two languages, 64 slots allow 32 feature domains.
 
@@ -32,14 +54,24 @@ config.missingTranslation = "";
 
 The pointer must remain valid while Lingo is initialized.
 
-## `preferPsram`
+## Migrating from v0.1.x
 
-PSRAM is preferred by default:
+Replace the old PSRAM boolean with Strata placement:
 
 ```cpp
+// v0.1.x
 config.preferPsram = true;
+
+// v0.2.0
+config.memory.allocation = Strata::Placement::PreferExternal;
 ```
 
-On ESP32, Lingo attempts `MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT` first when SPIRAM is available. If that allocation fails or PSRAM is unavailable, it falls back to normal `MALLOC_CAP_8BIT` heap.
+and:
 
-Set it to `false` to allocate the registry from normal 8-bit capable heap directly.
+```cpp
+// v0.1.x
+config.preferPsram = false;
+
+// v0.2.0
+config.memory.allocation = Strata::Placement::Internal;
+```

From 1b6930d3d7043a367433ac9f5954ed2bb122c0ef Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:26:30 +0200
Subject: [PATCH 15/25] Document Strata-backed Lingo memory ownership

---
 docs/memory.md | 38 +++++++++++++++++++++++++++++---------
 1 file changed, 29 insertions(+), 9 deletions(-)

diff --git a/docs/memory.md b/docs/memory.md
index 5727073..ce5d873 100644
--- a/docs/memory.md
+++ b/docs/memory.md
@@ -1,6 +1,6 @@
 # Memory
 
-Lingo is designed around static translation data and one bounded runtime registry.
+Lingo is designed around static translation data and one bounded runtime registry. All Lingo-owned dynamic memory routes through Strata.
 
 ## Static translation data
 
@@ -12,19 +12,35 @@ constexpr LingoTable EN{
 };
 ```
 
-The string literal and table live in static storage. Lookup does not allocate or copy the translation.
+The string literal and table live in static storage. Lingo does not copy them.
 
 ## Registry allocation
 
-`init()` allocates `maxTables` registry slots once.
+`init()` allocates `maxTables` registry slots once through Strata.
 
-With `preferPsram = true`, ESP32 allocation follows the same PSRAM-first policy used across ZekStack libraries:
+```cpp
+LingoConfig config;
+config.memory.allocation = Strata::Placement::PreferExternal;
+```
+
+The default is `PreferExternal`, preserving Lingo v0.1.x behavior: external memory is preferred and internal memory is a valid fallback.
+
+Use `Internal` to keep the registry in internal RAM, `Default` to use the backend default, or `RequireExternal` when internal fallback is not acceptable.
+
+If the requested placement cannot be satisfied, `init()` returns `LingoStatus::AllocationFailed` and Lingo remains uninitialized.
+
+## Requested placement and observed region
 
-1. use `MALLOC_CAP_SPIRAM | MALLOC_CAP_8BIT` when SPIRAM exists,
-2. fall back to `MALLOC_CAP_8BIT`,
-3. return `LingoStatus::AllocationFailed` if neither allocation succeeds.
+`getDiagnostics()` reports both the requested placement and the actual observed region:
 
-Host builds use `malloc`.
+```cpp
+const LingoDiag diag = lingo.getDiagnostics();
+
+Strata::Placement requested = diag.registryPlacement;
+Strata::Region actual = diag.registryRegion;
+```
+
+These are intentionally separate. For example, `PreferExternal` may resolve to `Region::Internal` when external allocation fails and fallback is allowed.
 
 ## Runtime allocation behavior
 
@@ -35,4 +51,8 @@ After successful `init()`:
 - `get()` does not allocate,
 - `setDefaultLanguage()` does not allocate.
 
-Only `init()` allocates registry storage and `end()` releases it.
+Only `init()` allocates registry storage and `end()` releases it through Strata.
+
+## Ownership boundary
+
+Lingo production sources must not call ESP-IDF heap capability APIs, `ps_malloc`, or raw C heap allocation directly. CI enforces this so future Lingo-owned allocations continue to use Strata.

From a79dce4c2df489aa71cdbe33f7101ecf97f78cb3 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:26:40 +0200
Subject: [PATCH 16/25] Update Basic example for Strata memory policy

---
 examples/Basic/Basic.ino | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/examples/Basic/Basic.ino b/examples/Basic/Basic.ino
index 28abcb0..305b92c 100644
--- a/examples/Basic/Basic.ino
+++ b/examples/Basic/Basic.ino
@@ -28,7 +28,7 @@ void setup() {
 
 	LingoConfig config;
 	config.defaultLanguage = Language::Hu;
-	config.preferPsram = true;
+	config.memory.allocation = Strata::Placement::PreferExternal;
 
 	if (!lingo.init(config)) {
 		return;
@@ -40,6 +40,13 @@ void setup() {
 	Serial.println(lingo.get(CommonKey::Key));
 	Serial.println(lingo.get(CommonKey::Example, Language::En));
 
+	const LingoDiag diag = lingo.getDiagnostics();
+	Serial.printf(
+	    "registry placement=%u region=%u\n",
+	    static_cast<unsigned>(diag.registryPlacement),
+	    static_cast<unsigned>(diag.registryRegion)
+	);
+
 	lingo.setDefaultLanguage(Language::En);
 	Serial.println(lingo.get(CommonKey::Key));
 }

From c58b46c6de19147b0abe854fae9ee75bc95e09a2 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:27:18 +0200
Subject: [PATCH 17/25] Update Lingo README for Strata v0.2.0

---
 README.md | 79 ++++++++++++++++++++++++++++++++++++++++++++-----------
 1 file changed, 64 insertions(+), 15 deletions(-)

diff --git a/README.md b/README.md
index 2043e74..333878c 100644
--- a/README.md
+++ b/README.md
@@ -2,7 +2,7 @@
 
 Lingo is a strongly typed, feature-oriented translation library for Arduino ESP32.
 
-It is designed for firmware where each feature owns a small translation table, lookup must stay allocation-free, and runtime registry storage should prefer PSRAM when available.
+It is designed for firmware where each feature owns a small translation table, lookup must stay allocation-free, and the bounded runtime registry should follow the same Strata memory policy used across ZekStack libraries.
 
 [![CI](https://github.com/ZekStack/lingo/actions/workflows/ci.yml/badge.svg)](https://github.com/ZekStack/lingo/actions/workflows/ci.yml)
 [![Release](https://img.shields.io/github/v/release/ZekStack/lingo?sort=semver)](https://github.com/ZekStack/lingo/releases)
@@ -12,14 +12,17 @@ It is designed for firmware where each feature owns a small translation table, l
 
 * **Feature-owned tables** - register many small translation domains per language instead of one global dictionary.
 * **Strongly typed keys** - each enum type is an isolated translation domain, so identical numeric values cannot collide across features.
-* **PSRAM-first registry** - `preferPsram` defaults to `true` and falls back to normal ESP32 heap when needed.
+* **Strata memory policy** - registry allocation uses `Strata::MemoryPolicy` and defaults to external-preferred allocation with safe internal fallback.
 * **Allocation-free lookup** - translation tables and strings are referenced directly; `get()` and `find()` do not allocate.
 * **No RTTI** - enum domains use unique static type tokens without `typeid` or `std::type_index`.
 * **Safe C strings** - `get()` always returns a valid `const char *`, suitable for logging and embedded display APIs.
 * **Explicit fallback** - requested-language lookup can fall back to the configured default language within the same feature domain.
+* **Placement diagnostics** - requested registry placement and the observed memory region are reported separately.
 
 ## Install
 
+Lingo v0.2.0 depends on [Strata](https://github.com/ZekStack/strata) v0.1.2.
+
 ### PlatformIO
 
 ```ini
@@ -37,16 +40,19 @@ build_unflags =
   -std=gnu++11
 ```
 
-### Arduino IDE
+Lingo's `library.json` pins Strata v0.1.2.
 
-Lingo is not published to Arduino Library Manager yet.
+### Arduino IDE
 
-Install it by downloading the repository ZIP or cloning it into:
+Lingo is not published to Arduino Library Manager yet. Install both repositories into the Arduino libraries directory:
 
 ```txt
 Arduino/libraries/Lingo
+Arduino/libraries/Strata
 ```
 
+Use Strata v0.1.2 with Lingo v0.2.0.
+
 ## Quick start
 
 ```cpp
@@ -78,7 +84,7 @@ constexpr LingoTable SOFTWARE_EN{
 void setup() {
 	LingoConfig config;
 	config.defaultLanguage = Language::Hu;
-	config.preferPsram = true;
+	config.memory.allocation = Strata::Placement::PreferExternal;
 
 	if (!lingo.init(config)) {
 		return;
@@ -90,10 +96,16 @@ void setup() {
 	const char *current = lingo.get(SoftwareKey::Install);
 	const char *english = lingo.get(SoftwareKey::Install, Language::En);
 
+	const LingoDiag diag = lingo.getDiagnostics();
+	Strata::Placement requested = diag.registryPlacement;
+	Strata::Region actual = diag.registryRegion;
+
 	lingo.setDefaultLanguage(Language::En);
 }
 ```
 
+`PreferExternal` is Lingo's default, so setting it explicitly is optional. It preserves the v0.1.x PSRAM-first behavior while allowing internal fallback.
+
 A second feature can define its own enum starting at the same numeric values without collisions:
 
 ```cpp
@@ -106,6 +118,21 @@ lingo.addTable(Language::Hu, TIME_HU);
 lingo.addTable(Language::En, TIME_EN);
 ```
 
+## Memory placement
+
+Lingo owns one dynamic allocation: the bounded translation-table registry created during `init()`.
+
+```cpp
+config.memory.allocation = Strata::Placement::Default;
+config.memory.allocation = Strata::Placement::Internal;
+config.memory.allocation = Strata::Placement::PreferExternal;
+config.memory.allocation = Strata::Placement::RequireExternal;
+```
+
+`RequireExternal` never silently falls back. If Strata cannot satisfy the placement, `init()` returns `LingoStatus::AllocationFailed` and Lingo remains uninitialized.
+
+Lingo creates no tasks, so `config.memory.taskStack` currently has no Lingo-owned task stack to control. The field remains part of the shared `Strata::MemoryPolicy` contract.
+
 ## Important notes
 
 > [!IMPORTANT]
@@ -115,7 +142,8 @@ lingo.addTable(Language::En, TIME_EN);
 * Size `maxTables` for the total number of registered language/domain pairs; each feature table in each language consumes one slot.
 * `get()` never returns `nullptr`; `find()` is the strict nullable lookup API.
 * `get(key, language)` falls back to the default language only within the same enum domain.
-* `init()` allocates a bounded registry once. With `preferPsram = true`, ESP32 PSRAM is attempted first and normal heap is the fallback.
+* `init()` allocates the complete bounded registry once through Strata.
+* `addTable()`, `get()`, `find()`, and `setDefaultLanguage()` do not allocate.
 * After startup registration, concurrent `get()`/`find()` calls are supported. Do not mutate the table registry concurrently with lookups.
 * Translation bytes are passed through unchanged, including UTF-8 text.
 
@@ -123,7 +151,7 @@ lingo.addTable(Language::En, TIME_EN);
 
 | Example | Description |
 | --- | --- |
-| `Basic` | Initialize Lingo, register HU/EN tables, and switch the default language. |
+| `Basic` | Initialize Lingo with Strata placement, register HU/EN tables, inspect registry diagnostics, and switch the default language. |
 | `FeatureTables` | Register multiple feature domains per language with overlapping numeric key values. |
 | `Fallback` | Demonstrate strict lookup and same-domain default-language fallback. |
 
@@ -137,12 +165,12 @@ examples/Basic
 
 | Document | Description |
 | --- | --- |
-| [`docs/getting-started.md`](docs/getting-started.md) | First integration and table registration. |
-| [`docs/api.md`](docs/api.md) | Public types and methods. |
-| [`docs/configuration.md`](docs/configuration.md) | Registry sizing, fallback string, and PSRAM preference. |
+| [`docs/getting-started.md`](docs/getting-started.md) | First integration, Strata memory placement, and table registration. |
+| [`docs/api.md`](docs/api.md) | Public types, methods, and diagnostics. |
+| [`docs/configuration.md`](docs/configuration.md) | Memory policy, registry sizing, and fallback string. |
 | [`docs/tables-and-domains.md`](docs/tables-and-domains.md) | Feature-domain identity and registration rules. |
 | [`docs/fallback.md`](docs/fallback.md) | Exact `get()` and `find()` resolution behavior. |
-| [`docs/memory.md`](docs/memory.md) | Static translations, bounded allocation, and PSRAM behavior. |
+| [`docs/memory.md`](docs/memory.md) | Static translations, bounded allocation, and Strata ownership. |
 | [`docs/thread-safety.md`](docs/thread-safety.md) | Supported runtime concurrency and lifecycle rules. |
 | [`docs/troubleshooting.md`](docs/troubleshooting.md) | Common registration and lookup failures. |
 
@@ -158,9 +186,30 @@ const char *value = lingo.get(SoftwareKey::Install);
 const char *hu = lingo.get(SoftwareKey::Install, Language::Hu);
 const char *strict = lingo.find(SoftwareKey::Install, Language::Hu);
 
+LingoDiag diag = lingo.getDiagnostics();
 lingo.setDefaultLanguage(Language::En);
 ```
 
+## Migrating from v0.1.x
+
+```cpp
+// v0.1.x: prefer PSRAM with internal fallback
+config.preferPsram = true;
+
+// v0.2.0
+config.memory.allocation = Strata::Placement::PreferExternal;
+```
+
+```cpp
+// v0.1.x: internal heap
+config.preferPsram = false;
+
+// v0.2.0
+config.memory.allocation = Strata::Placement::Internal;
+```
+
+`Lingo::preferPsram()` was removed. Use `getDiagnostics().registryPlacement` for requested policy and `getDiagnostics().registryRegion` for the observed location.
+
 ## Compatibility
 
 | Item | Support |
@@ -168,12 +217,12 @@ lingo.setDefaultLanguage(Language::En);
 | Framework | Arduino ESP32 |
 | Platform | `espressif32` |
 | Language | C++20 |
-| Dependencies | none |
+| Dependencies | Strata v0.1.2 |
 | RTTI | not required |
 | Exceptions | not used for public error handling |
-| PSRAM | preferred for registry allocation by default |
+| Registry default | `Strata::Placement::PreferExternal` |
 | Runtime lookup allocation | none |
-| Status | initial `0.1.0` development |
+| Status | v0.2.0 Strata memory-policy migration |
 
 ## License
 

From efbc1e5216be767f9a6e64bc0230fc5af6ba8bdc Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:28:17 +0200
Subject: [PATCH 18/25] Document Strata allocation failures

---
 docs/troubleshooting.md | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/docs/troubleshooting.md b/docs/troubleshooting.md
index 2d5f827..990fa7e 100644
--- a/docs/troubleshooting.md
+++ b/docs/troubleshooting.md
@@ -1,5 +1,15 @@
 # Troubleshooting
 
+## `InvalidConfig`
+
+`init()` rejects zero `maxTables`, a null `missingTranslation`, an overflowing registry size, or an invalid `Strata::MemoryPolicy`. Use one of the defined `Strata::Placement` values for both policy fields.
+
+## `AllocationFailed`
+
+Strata could not allocate the bounded registry with the requested policy.
+
+If `config.memory.allocation == Strata::Placement::RequireExternal`, external memory is mandatory and Lingo does not fall back to internal RAM. Use `PreferExternal` when internal fallback is acceptable or `Internal` when the registry should stay in internal memory.
+
 ## `TableAlreadyRegistered`
 
 Only one table may be registered for each `{language, key enum type}` pair. Merge that feature's translations into one table for the language.

From 1380b4027005d4a2d9d304f4bb18df518919840c Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:28:57 +0200
Subject: [PATCH 19/25] Fix release notes extraction in Lingo CI

---
 .github/workflows/ci.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index abde632..2fcafa3 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -221,8 +221,8 @@ jobs:
         run: |
           VERSION="${GITHUB_REF_NAME#v}"
           awk -v version="$VERSION" '
-            $0 == "## " {if (capture) exit}
             $0 == "## " version {capture=1; next}
+            capture && /^## / {exit}
             capture {print}
           ' CHANGELOG.md > /tmp/release-notes.md
           gh release create "$GITHUB_REF_NAME" \

From 1cf5720fafb45e99659b3fdfee2d56e613aa7ac7 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:31:53 +0200
Subject: [PATCH 20/25] Fix clang-format in Lingo init validation

---
 src/Lingo.cpp | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/src/Lingo.cpp b/src/Lingo.cpp
index bd2a2f5..3b1ba61 100644
--- a/src/Lingo.cpp
+++ b/src/Lingo.cpp
@@ -32,10 +32,8 @@ LingoResult Lingo::init(const LingoConfig &config) {
 		);
 	}
 
-	if (
-		config.maxTables == 0 ||
-		config.missingTranslation == nullptr ||
-		!Strata::validMemoryPolicy(config.memory)) {
+	if (config.maxTables == 0 || config.missingTranslation == nullptr ||
+	    !Strata::validMemoryPolicy(config.memory)) {
 		return LingoResult::failure(LingoStatus::InvalidConfig, "invalid lingo configuration");
 	}
 

From a9d200f50dfbf9b9d3e341ffa39877d63b2ad1c4 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 09:33:52 +0200
Subject: [PATCH 21/25] Migrate FeatureTables example to Strata memory policy

---
 examples/FeatureTables/FeatureTables.ino | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/FeatureTables/FeatureTables.ino b/examples/FeatureTables/FeatureTables.ino
index 58bd623..52b5a40 100644
--- a/examples/FeatureTables/FeatureTables.ino
+++ b/examples/FeatureTables/FeatureTables.ino
@@ -56,7 +56,7 @@ void setup() {
 	LingoConfig config;
 	config.defaultLanguage = Language::Hu;
 	config.maxTables = 8;
-	config.preferPsram = true;
+	config.memory.allocation = Strata::Placement::PreferExternal;
 
 	if (!lingo.init(config)) {
 		return;

From 02038afdcd43d8e1d08a3a6a6284b540006ceb09 Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 10:30:53 +0200
Subject: [PATCH 22/25] Fix PlatformIO CI disk exhaustion

---
 .github/workflows/ci.yml | 20 +++++++++++---------
 1 file changed, 11 insertions(+), 9 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2fcafa3..caeee77 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -113,6 +113,9 @@ jobs:
   build-examples:
     runs-on: [self-hosted, zekstack-ci]
     needs: [source-audit, host-tests]
+    env:
+      PLATFORMIO_CORE_DIR: ${{ runner.temp }}/lingo-platformio
+      PIP_CACHE_DIR: ${{ runner.temp }}/lingo-pip-cache
     strategy:
       fail-fast: false
       matrix:
@@ -122,19 +125,15 @@ jobs:
           - esp32-c3-devkitm-1
           - esp32-p4-evboard
     steps:
+      - name: Clean stale PIOArduino state
+        run: |
+          rm -rf "${HOME}/.platformio" "${HOME}/.cache/pip"
+          rm -rf "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
+          mkdir -p "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:
           python-version: '3.13'
-      - name: Cache PIOArduino
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.platformio
-            ~/.cache/pip
-          key: ${{ runner.os }}-pioarduino-${{ env.PIOARDUINO_VERSION }}-${{ env.PIOARDUINO_PLATFORM_VERSION }}-${{ hashFiles('**/library.json') }}
-          restore-keys: |
-            ${{ runner.os }}-pioarduino-${{ env.PIOARDUINO_VERSION }}-${{ env.PIOARDUINO_PLATFORM_VERSION }}-
       - name: Install PIOArduino
         run: |
           python -m pip install --upgrade "pioarduino==${PIOARDUINO_VERSION}"
@@ -151,6 +150,9 @@ jobs:
               --project-option "build_unflags=-std=gnu++11" \
               --project-option "build_flags=-std=gnu++20"
           done
+      - name: Clean PIOArduino temporary state
+        if: always()
+        run: rm -rf "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
 
   arduino-cli:
     runs-on: [self-hosted, zekstack-ci]

From daeb7d4a37635358b3f979ba2165ce0aa6bddfbd Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 10:33:30 +0200
Subject: [PATCH 23/25] Fix CI workflow validation

---
 .github/workflows/ci.yml | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index caeee77..a5949df 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -113,9 +113,6 @@ jobs:
   build-examples:
     runs-on: [self-hosted, zekstack-ci]
     needs: [source-audit, host-tests]
-    env:
-      PLATFORMIO_CORE_DIR: ${{ runner.temp }}/lingo-platformio
-      PIP_CACHE_DIR: ${{ runner.temp }}/lingo-pip-cache
     strategy:
       fail-fast: false
       matrix:
@@ -127,9 +124,13 @@ jobs:
     steps:
       - name: Clean stale PIOArduino state
         run: |
+          PLATFORMIO_CORE_DIR="${RUNNER_TEMP}/lingo-platformio"
+          PIP_CACHE_DIR="${RUNNER_TEMP}/lingo-pip-cache"
           rm -rf "${HOME}/.platformio" "${HOME}/.cache/pip"
           rm -rf "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
           mkdir -p "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
+          echo "PLATFORMIO_CORE_DIR=${PLATFORMIO_CORE_DIR}" >> "${GITHUB_ENV}"
+          echo "PIP_CACHE_DIR=${PIP_CACHE_DIR}" >> "${GITHUB_ENV}"
       - uses: actions/checkout@v4
       - uses: actions/setup-python@v5
         with:

From 59aec3ad45eabaeaea9b92204967d63face7bfea Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 10:37:38 +0200
Subject: [PATCH 24/25] Isolate embedded CI toolchains

---
 .github/workflows/ci.yml | 37 ++++++++++++++++++++++---------------
 1 file changed, 22 insertions(+), 15 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a5949df..a787045 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -8,8 +8,8 @@ on:
   workflow_dispatch:
 
 concurrency:
-  group: lingo-${{ github.ref }}
-  cancel-in-progress: false
+  group: lingo-${{ github.workflow }}-${{ github.head_ref || github.ref_name }}
+  cancel-in-progress: true
 
 env:
   ARDUINO_BOARD_MANAGER_ADDITIONAL_URLS: https://espressif.github.io/arduino-esp32/package_esp32_index.json
@@ -122,11 +122,11 @@ jobs:
           - esp32-c3-devkitm-1
           - esp32-p4-evboard
     steps:
-      - name: Clean stale PIOArduino state
+      - name: Prepare isolated PIOArduino state
         run: |
           PLATFORMIO_CORE_DIR="${RUNNER_TEMP}/lingo-platformio"
           PIP_CACHE_DIR="${RUNNER_TEMP}/lingo-pip-cache"
-          rm -rf "${HOME}/.platformio" "${HOME}/.cache/pip"
+          rm -rf "${HOME}/.platformio" "${HOME}/.cache/pip" "${HOME}/.arduino15" "${HOME}/.cache/arduino"
           rm -rf "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
           mkdir -p "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
           echo "PLATFORMIO_CORE_DIR=${PLATFORMIO_CORE_DIR}" >> "${GITHUB_ENV}"
@@ -171,19 +171,21 @@ jobs:
           - fqbn: esp32:esp32:esp32p4
             name: esp32-p4-evboard
     steps:
+      - name: Prepare isolated Arduino CLI state
+        run: |
+          ARDUINO_DATA_DIR="${RUNNER_TEMP}/lingo-arduino-data"
+          ARDUINO_DOWNLOADS_DIR="${RUNNER_TEMP}/lingo-arduino-downloads"
+          ARDUINO_USER_DIR="${RUNNER_TEMP}/lingo-arduino-user"
+          rm -rf "${HOME}/.platformio" "${HOME}/.cache/pip" "${HOME}/.arduino15" "${HOME}/.cache/arduino"
+          rm -rf "${ARDUINO_DATA_DIR}" "${ARDUINO_DOWNLOADS_DIR}" "${ARDUINO_USER_DIR}"
+          mkdir -p "${ARDUINO_DATA_DIR}" "${ARDUINO_DOWNLOADS_DIR}" "${ARDUINO_USER_DIR}"
+          echo "ARDUINO_DIRECTORIES_DATA=${ARDUINO_DATA_DIR}" >> "${GITHUB_ENV}"
+          echo "ARDUINO_DIRECTORIES_DOWNLOADS=${ARDUINO_DOWNLOADS_DIR}" >> "${GITHUB_ENV}"
+          echo "ARDUINO_DIRECTORIES_USER=${ARDUINO_USER_DIR}" >> "${GITHUB_ENV}"
       - uses: actions/checkout@v4
       - uses: arduino/setup-arduino-cli@v2
         with:
           version: ${{ env.ARDUINO_CLI_VERSION }}
-      - name: Cache Arduino CLI packages
-        uses: actions/cache@v4
-        with:
-          path: |
-            ~/.arduino15
-            ~/.cache/arduino
-          key: ${{ runner.os }}-arduino-cli-${{ env.ARDUINO_CLI_VERSION }}-esp32-${{ env.ESP32_CORE_VERSION }}
-          restore-keys: |
-            ${{ runner.os }}-arduino-cli-${{ env.ARDUINO_CLI_VERSION }}-esp32-
       - name: Install ESP32 core
         run: |
           arduino-cli core update-index
@@ -191,8 +193,7 @@ jobs:
       - name: Add local libraries to sketchbook
         run: |
           set -e
-          SKETCHBOOK_DIR="${HOME}/Arduino"
-          rm -rf "$SKETCHBOOK_DIR/libraries/Lingo" "$SKETCHBOOK_DIR/libraries/Strata"
+          SKETCHBOOK_DIR="${ARDUINO_DIRECTORIES_USER}"
           mkdir -p "$SKETCHBOOK_DIR/libraries/Lingo"
           rsync -a --delete --exclude ".git" ./ "$SKETCHBOOK_DIR/libraries/Lingo/"
           git clone --depth 1 --branch "${STRATA_VERSION}" \
@@ -209,6 +210,12 @@ jobs:
               --build-property "compiler.cpp.extra_flags=-std=gnu++20" \
               "$sketch"
           done
+      - name: Clean Arduino CLI temporary state
+        if: always()
+        run: |
+          rm -rf "${ARDUINO_DIRECTORIES_DATA}" \
+            "${ARDUINO_DIRECTORIES_DOWNLOADS}" \
+            "${ARDUINO_DIRECTORIES_USER}"
 
   release:
     if: startsWith(github.ref, 'refs/tags/v')

From 44b06986538e5eb0429eac623b92a917b994b5fe Mon Sep 17 00:00:00 2001
From: DrRandom <37899881+zekageri@users.noreply.github.com>
Date: Tue, 8 Sep 2026 14:15:13 +0200
Subject: [PATCH 25/25] Fix self-hosted runner cache cleanup

---
 .github/workflows/ci.yml | 2 --
 1 file changed, 2 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index a787045..b03814f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -126,7 +126,6 @@ jobs:
         run: |
           PLATFORMIO_CORE_DIR="${RUNNER_TEMP}/lingo-platformio"
           PIP_CACHE_DIR="${RUNNER_TEMP}/lingo-pip-cache"
-          rm -rf "${HOME}/.platformio" "${HOME}/.cache/pip" "${HOME}/.arduino15" "${HOME}/.cache/arduino"
           rm -rf "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
           mkdir -p "${PLATFORMIO_CORE_DIR}" "${PIP_CACHE_DIR}"
           echo "PLATFORMIO_CORE_DIR=${PLATFORMIO_CORE_DIR}" >> "${GITHUB_ENV}"
@@ -176,7 +175,6 @@ jobs:
           ARDUINO_DATA_DIR="${RUNNER_TEMP}/lingo-arduino-data"
           ARDUINO_DOWNLOADS_DIR="${RUNNER_TEMP}/lingo-arduino-downloads"
           ARDUINO_USER_DIR="${RUNNER_TEMP}/lingo-arduino-user"
-          rm -rf "${HOME}/.platformio" "${HOME}/.cache/pip" "${HOME}/.arduino15" "${HOME}/.cache/arduino"
           rm -rf "${ARDUINO_DATA_DIR}" "${ARDUINO_DOWNLOADS_DIR}" "${ARDUINO_USER_DIR}"
           mkdir -p "${ARDUINO_DATA_DIR}" "${ARDUINO_DOWNLOADS_DIR}" "${ARDUINO_USER_DIR}"
           echo "ARDUINO_DIRECTORIES_DATA=${ARDUINO_DATA_DIR}" >> "${GITHUB_ENV}"