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/error.yaml

@@ -0,0 +1,15 @@
+type: object
+required:
+  - code
+  - message
+properties:
+  code:
+    type: string
+    description: Error code (e.g., unauthorized, invalid_payload, already_enrolled)
+    example: unauthorized
+  message:
+    type: string
+    example: Missing or invalid token
+  details:
+    type: object
+    additionalProperties: true