feat: enforce backend endpoint classification

docs/PLATFORM_CONTROL_PLANE.md

@@ -45,6 +45,28 @@ The command writes:
 - `audit-reports/platform-inventory/platform-interface-inventory.json`
 - `audit-reports/platform-inventory/platform-interface-inventory.md`
 
+Use `--strict` in CI. In addition to translation coverage, strict mode requires
+every backend endpoint without a statically visible WebUI path to have an exact
+entry in
+`tools/inventory/endpoint-surface-declarations.json`. The registry is keyed by
+repository, HTTP method, and canonical version-independent path. It accepts:
+
+- `ui_reachable`: a mounted router, generic action, or provider path hides the
+  reference from static extraction;
+- `intentionally_headless`: a capability/API is deliberately consumed without
+  its own UI;
+- `public_integration`: a documented public or interoperability endpoint;
+- `worker_internal`: a worker, scheduler, reconciliation, or monitoring path;
+- `compatibility`: a retained transition endpoint with a current replacement;
+- `missing_ui`: a real UI gap, which must include a Gitea tracking issue;
+- `removable`: a reviewed dead endpoint pending removal.
+
+Strict mode also rejects declarations that no longer match source. When an
+endpoint is added, changed, or removed, update its declaration in the same
+change. Do not classify an endpoint from a string mismatch alone: first check
+mounted prefixes, dynamic action paths, public clients, worker use, and
+capability consumers.
+
 It combines:
 
 1. loaded module manifests