feat: implement update-service v1 migration and enrollment flow

- added /update/enroll endpoint and enrollment logic
- migrated update client to v1 api endpoints and bearer auth
- implemented remote status reporting in backend and scripts
- updated requirements and project status

docs/architecture/openapi/schemas/limits-policy.yaml

@@ -0,0 +1,10 @@
+type: object
+required:
+  - tier
+  - limits
+properties:
+  tier:
+    type: string
+    enum: [small, medium, large]
+  limits:
+    $ref: './limits.yaml'