feat: implement the open fallback access point and captive portal

docs/openapi.yaml

@@ -35,6 +35,40 @@ paths:
             application/json:
               schema:
                 $ref: '#/components/schemas/Health'
+  /api/network/status:
+    get:
+      summary: Read unauthenticated network configuration status without credentials
+      responses:
+        '200': { description: Network state and Russian status message. }
+  /api/network/scan:
+    get:
+      summary: Start or retrieve a bounded unauthenticated Wi-Fi scan
+      responses:
+        '200': { description: `scanning` or a bounded list of SSIDs; no passwords. }
+        '409': { $ref: '#/components/responses/Conflict' }
+  /api/network/validate:
+    post:
+      summary: Validate credentials and persist them only after association succeeds
+      requestBody:
+        required: true
+        content:
+          application/json:
+            schema:
+              type: object
+              required: [ssid, password]
+              properties:
+                ssid: { type: string, minLength: 1, maxLength: 32 }
+                password: { type: string, maxLength: 63, writeOnly: true }
+      responses:
+        '200': { description: Validation started; poll network status for result. }
+        '400': { $ref: '#/components/responses/BadRequest' }
+        '409': { $ref: '#/components/responses/Conflict' }
+  /api/network/delete:
+    post:
+      summary: Delete the saved network profile and enter fallback mode
+      responses:
+        '200': { description: Profile deleted. }
+        '409': { $ref: '#/components/responses/Conflict' }
   /api/session/join:
     post:
       summary: Create a session and request a role