Move ingress canary reads to FastAPI

[cbusillo]

Summary

• Move ingress canary route record list/read endpoints to native FastAPI handlers.
• Preserve ingress_canary_route.read authorization and record-store read semantics, including list filters and bounded limit parsing.
• Remove the retired WSGI read matcher/handler and stale list-store requirement while keeping ingress canary apply on the legacy write path.
• Update service-boundary and compatibility-retirement docs for the v2 cutover checkpoint.

Refs #1322

Validation

• uv run python -m unittest tests.test_http_app.FastApiIngressCanaryRouteReadTests tests.test_service.LaunchplaneServiceTests.test_ingress_canary_route_record_apply_stores_route_authority tests.test_service.LaunchplaneServiceTests.test_ingress_canary_route_apply_resolves_profile_and_edge_endpoint tests.test_service.LaunchplaneServiceTests.test_ingress_canary_route_apply_idempotency_ignores_record_changes tests.test_service.LaunchplaneServiceTests.test_ingress_canary_route_apply_rejects_missing_profile tests.test_service.LaunchplaneServiceTests.test_ingress_canary_route_apply_rejects_disabled_profile tests.test_service.LaunchplaneServiceTests.test_ingress_canary_route_apply_authorizes_before_profile_lookup tests.test_service.LaunchplaneServiceTests.test_ingress_canary_route_read_routes_are_retired_from_legacy_wsgi_app
• uv run --extra dev ruff check --exit-zero control_plane/http_app.py control_plane/service.py tests/test_http_app.py tests/test_service.py docs/service-boundary.md docs/compatibility-retirement.md
• 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 ruff check control_plane/http_app.py control_plane/service.py tests/test_http_app.py tests/test_service.py docs/service-boundary.md docs/compatibility-retirement.md
• uv run --extra dev mypy control_plane tests
• uv run --extra dev ruff check .
• uv run python -m unittest
• JetBrains changed-files closeout: clean
• Review agents: antigravity and claude-sonnet both GREEN TO MERGE