docs(alpha,#1408): refresh canary lane state

[joelteply]

Summary

• refresh Alpha Gap current-read snapshot from 2026-05-16 to 2026-05-18 canary state
• mark Lane D and Lane F as active/in-progress with landed PRs and next blockers
• record main-promotion receipt requirements from fix(ci): add main promotion GPU release gate #1399, including Main promotion: collect linux/amd64 CUDA receipt from Windows/WSL Nvidia host #1410 CUDA receipt
• record stale failed-smoke PRs (fix(install): align tier name to registry canon + pass TIER to model-init + fail loud on unknown tier #1085, fix(mac): gate native LiveKit bridge behind explicit profile #1071, fix(mac): run livekit bridge natively #1026) as hygiene targets
• add oxidizer: migrate ToolRegistry semantic search to Rust cognition/tool-embedding #1411/feat(cognition,#1411): tool_embedding PR-1 — pure types + cosine_similarity + threshold #1413 ToolRegistry oxidizer note

Validation

• git diff --check
• precommit: TypeScript compilation passed; browser tests skipped because JTAG/core IPC were not reachable

Closes #1408