Migrate Tempo memory ownership to Strata

[zekageri]

Summary

• bump Tempo to v0.2.0 and require Strata v0.1.2
• adopt Strata::MemoryPolicy for scheduler metadata and task-stack placement with PreferExternal defaults
• route deterministic scheduler containers through Strata-backed storage
• replace raw scheduler service, worker-pool, and dedicated-task creation with Strata::FreeRTOS::Task
• replace dynamic queues and the queue-set wake path with Strata queues plus a binary wake semaphore
• move scheduler command completion signaling to Strata::FreeRTOS::BinarySemaphore
• route scheduler implementation objects, command objects, task items, runtime state, and callback holders through Strata ownership
• preserve external task-deletion handoff so Strata task owners release stacks/TCBs safely
• add CI dependency setup and source audits that reject the legacy allocation/task paths

Memory policy

Tempo v0.2.0 intentionally defaults movable storage and task stacks to Strata::Placement::PreferExternal. Strata-owned FreeRTOS control structures remain internal according to Strata's safety contract.

Compatibility

This is the v0.2.0 memory-policy migration and intentionally establishes the shared Strata placement vocabulary rather than retaining Tempo-specific task-stack PSRAM policy.

Validation

CI covers host regressions and ESP32/ESP32-S3/ESP32-C3/ESP32-P4 example builds with Strata v0.1.2. Follow-up CI fixes also make the source audit distinguish raw free() from the intended Strata::free() path and update README/version documentation for 0.2.0.

[zekageri]

CI failure investigation: the failing runs never reached checkout or repository code; they failed in GitHub Actions Set up job on the self-hosted zekstack-ci runners. I re-ran the failed workflows. Host Tests and Lint are now green, and the main CI rerun has passed source-audit, version-check, and host-tests; the ESP32 build matrix is still running. No repository code change was required for this failure.