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/paths/admin-enrollment-tokens-export.yaml

@@ -0,0 +1,31 @@
+get:
+  summary: Export enrollment token
+  x-auth-scopes: [admin]
+  parameters:
+    - name: token_id
+      in: path
+      required: true
+      schema:
+        type: string
+  responses:
+    '200':
+      description: Token file
+      content:
+        text/plain:
+          schema:
+            type: string
+            example: enroll_6f3d2c...
+    '401':
+      description: Unauthorized
+      x-error-codes: [unauthorized]
+      content:
+        application/json:
+          schema:
+            $ref: '../schemas/error.yaml'
+    '404':
+      description: Not Found
+      x-error-codes: [not_found]
+      content:
+        application/json:
+          schema:
+            $ref: '../schemas/error.yaml'