Squash-merge the verified #412 eval coverage implementation. Required validate and paired evaluation checks passed at exact head b43ac564a5919a0f23fdab49ba052d7c514915cb; droid-review BYOK failure had no findings and is advisory.
* feat: add portable ESP32 development skill
Add source-backed workflows, safe templates, native CLI routing, and a read-only preflight for ESP32 hardware and firmware work.\n\nAI assistance: research, drafting, implementation, and review used OpenAI Codex and delegated DeepSeek agents under human direction.
* docs: harden ESP32 family and security guidance
Add source-backed family traps, brownout, calibration, USB recovery, and security-mode boundaries found during independent review.\n\nAI assistance: independent audits and drafting used delegated DeepSeek agents and OpenAI Codex under human direction.