Add "Get My Active Self-Serve Wash" endpoint and corresponding tests

- Introduced a new `/modules/self-serve/lane/wash/my-active-wash` endpoint to retrieve the authenticated customer's active self-serve wash.
- Implemented authentication and permission checks for secure access.
- Added detailed response handling for various scenarios, including 401, 403, and 404 statuses.
- Extended API documentation and OpenAPI spec to support the new endpoint.
- Updated unit and API tests to validate endpoint functionality and route wiring.

openapi.yaml

@@ -8843,6 +8843,47 @@ paths:
         '403':
           $ref: '#/components/responses/Forbidden'
 
+  /modules/self-serve/lane/wash/my-active-wash:
+    get:
+      tags:
+        - Modules
+      summary: Get the authenticated customer's active self-serve wash
+      description: |
+        Returns the latest active self-serve wash for the authenticated customer,
+        without requiring the frontend to know or poll a lane id.
+      operationId: getMyActiveSelfServeWash
+      responses:
+        '200':
+          description: Active self-serve wash details resolved
+          content:
+            application/json:
+              schema:
+                type: object
+                properties:
+                  lane_id:
+                    type: integer
+                  status:
+                    type: string
+                  in_progress:
+                    type: boolean
+                  elapsed_minutes:
+                    type: integer
+                  session:
+                    type: object
+                    nullable: true
+                  customer:
+                    type: object
+                    nullable: true
+                  vehicle:
+                    type: object
+                    nullable: true
+        '401':
+          $ref: '#/components/responses/Unauthorized'
+        '403':
+          $ref: '#/components/responses/Forbidden'
+        '404':
+          $ref: '#/components/responses/NotFound'
+
   /modules/self-serve/sessions:
     get:
       tags:
@@ -18688,4 +18729,3 @@ components:
         data:
           $ref: '#/components/schemas/DepartmentDailyReportOutsideHoursTrendPayload'
 
-