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/enrollment-token-create-response.yaml

@@ -0,0 +1,11 @@
+type: object
+required:
+  - token
+  - token_meta
+properties:
+  token:
+    type: string
+    description: One-time plaintext enrollment token
+    example: enroll_6f3d2c...
+  token_meta:
+    $ref: './enrollment-token.yaml'