Move Every Code reads to FastAPI

[cbusillo]

Summary

• move Every Code work request, PR feedback, preview gate, notification attempt, summary, and preview readiness reads into the native FastAPI app
• retire the matching legacy WSGI read routes and worker-token GET bypass while preserving WSGI write/worker POST flows
• remove stale GET matcher compatibility for notification-policy apply routes and update service boundary docs

Validation

• uv run --extra dev ruff check .
• uv run --extra dev ruff format --check control_plane/http_app.py control_plane/service.py tests/test_http_app.py tests/test_service.py
• git diff --check
• uv run --extra dev mypy control_plane tests
• uv run python -m unittest
• JetBrains changed-files closeout clean
• final review agents green