docs(swagger): document account label endpoints (#13760)

Documents the missing account-level label CRUD endpoints in Chatwoot's
Swagger output so label management is discoverable alongside the
existing contact and conversation label APIs.

Fixes: none
Closes: none

Why
The account-level label API already exists in Chatwoot, but it was
missing from the published Swagger spec. That made label management
harder to discover even though contact and conversation label assignment
endpoints were already documented.

What this change does
- adds a `Labels` tag to the application Swagger docs
- adds the label resource and create/update payload schemas
- documents `GET/POST /api/v1/accounts/{account_id}/labels`
- documents `GET/PATCH/DELETE /api/v1/accounts/{account_id}/labels/{id}`
- regenerates the compiled Swagger JSON artifacts

Validation
- rebuilt the Swagger JSON from the source YAML
- verified the new label endpoints appear in `swagger/swagger.json`
- verified the new label endpoints appear in
`swagger/tag_groups/application_swagger.json`
- started the local Rails server and confirmed `/swagger` and
`/swagger/swagger.json` return `200 OK`

swagger/paths/application/labels/create.yml

@@ -0,0 +1,26 @@
+tags:
+  - Labels
+operationId: create-a-label
+summary: Create a label
+security:
+  - userApiKey: []
+description: Create a label in the account
+requestBody:
+  required: true
+  content:
+    application/json:
+      schema:
+        $ref: '#/components/schemas/label_create_update_payload'
+responses:
+  '200':
+    description: Success
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/label'
+  '401':
+    description: Unauthorized
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'

swagger/paths/application/labels/delete.yml

@@ -0,0 +1,22 @@
+tags:
+  - Labels
+operationId: delete-a-label
+summary: Delete a label
+security:
+  - userApiKey: []
+description: Delete a label from the account
+responses:
+  '200':
+    description: Success
+  '401':
+    description: Unauthorized
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'
+  '404':
+    description: The label does not exist in the account
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'

swagger/paths/application/labels/index.yml

@@ -0,0 +1,26 @@
+tags:
+  - Labels
+operationId: list-all-labels
+summary: List all labels
+security:
+  - userApiKey: []
+description: List all labels available in the current account
+responses:
+  '200':
+    description: Success
+    content:
+      application/json:
+        schema:
+          type: object
+          properties:
+            payload:
+              type: array
+              description: Array of labels
+              items:
+                $ref: '#/components/schemas/label'
+  '401':
+    description: Unauthorized
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'

swagger/paths/application/labels/show.yml

@@ -0,0 +1,26 @@
+tags:
+  - Labels
+operationId: get-details-of-a-single-label
+summary: Get a label
+security:
+  - userApiKey: []
+description: Get the details of a label in the account
+responses:
+  '200':
+    description: Success
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/label'
+  '401':
+    description: Unauthorized
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'
+  '404':
+    description: The given label ID does not exist in the account
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'

swagger/paths/application/labels/update.yml

@@ -0,0 +1,26 @@
+tags:
+  - Labels
+operationId: update-a-label
+summary: Update a label
+security:
+  - userApiKey: []
+description: Update a label's attributes
+requestBody:
+  required: true
+  content:
+    application/json:
+      schema:
+        $ref: '#/components/schemas/label_create_update_payload'
+responses:
+  '200':
+    description: Success
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/label'
+  '401':
+    description: Unauthorized
+    content:
+      application/json:
+        schema:
+          $ref: '#/components/schemas/bad_request_error'

swagger/paths/index.yml

@@ -438,6 +438,30 @@
   delete:
     $ref: ./application/inboxes/inbox_members/delete.yml
 
+# Labels
+/api/v1/accounts/{account_id}/labels:
+  parameters:
+    - $ref: '#/components/parameters/account_id'
+  get:
+    $ref: ./application/labels/index.yml
+  post:
+    $ref: ./application/labels/create.yml
+/api/v1/accounts/{account_id}/labels/{id}:
+  parameters:
+    - $ref: '#/components/parameters/account_id'
+    - name: id
+      in: path
+      required: true
+      schema:
+        type: number
+      description: ID of the label
+  get:
+    $ref: ./application/labels/show.yml
+  patch:
+    $ref: ./application/labels/update.yml
+  delete:
+    $ref: ./application/labels/delete.yml
+
 # Messages
 /api/v1/accounts/{account_id}/conversations/{conversation_id}/messages:
   parameters: