auth: add community token service seam

TASKS.md

@@ -37,6 +37,15 @@ Verification:
 - unit tests for credential-kind enforcement;
 - docs sync check.
 
+Progress:
+- done:
+  - stable DTO и Community stub endpoints для `POST /mcp-auth/v1/token` и `POST /mcp-auth/v1/token/one-time`
+  - structured `403 forbidden` contract с `edition`, `machine_access_mode` и `upgrade_required`
+- pending:
+  - abstraction для token verification в `mcp-server`
+  - capability-gated UI/API surface для premium machine access
+  - final separation of Community `standard` flow from commercial `elevated/strict`
+
 ## Planned
 
 ### `feat/frontend-commercial-polish`