Add static FreeRTOS binary semaphore support for v0.1.2

[zekageri]

Summary

• add move-only Strata::FreeRTOS::BinarySemaphore ownership using xSemaphoreCreateBinaryStatic() and internal Strata-backed StaticSemaphore_t storage
• add task and ISR take/give APIs with explicit bool failure reporting and initially-empty semantics
• extend FreeRTOS and ESP32 test fakes, including internal allocation failure injection
• add host and ESP32 backend contracts and wire them into CI
• add an ESP32 multi-target example and binary semaphore documentation
• bump library metadata/changelog to 0.1.2 and make release instructions derive the tag version from metadata

Release scope

This PR prepares v0.1.2; it does not create or push the release tag.

Validation

CI covers metadata validation, source audits, host contracts, ESP32 backend contracts, and the ESP32/ESP32-S3/ESP32-C3/ESP32-P4 example matrix.