feat: add permission profile list api (#23412)

## Why

Clients need a typed permission-profile catalog instead of
reconstructing that state from config internals.

## What changed

- Added `permissionProfile/list` to the app-server v2 protocol with
cursor pagination and optional `cwd`.
- The list response includes built-in permission profiles plus
config-defined `[permissions.<id>]` profiles from the effective config
for the request context.
- Permission profiles keep optional `description` metadata for display
purposes.
- App-server docs and schema fixtures are updated for the new RPC.

codex-rs/app-server-protocol/schema/json/ClientRequest.json

@@ -1541,6 +1541,34 @@
       ],
       "type": "string"
     },
+    "PermissionProfileListParams": {
+      "properties": {
+        "cursor": {
+          "description": "Opaque pagination cursor returned by a previous call.",
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "cwd": {
+          "description": "Optional working directory to resolve project config layers.",
+          "type": [
+            "string",
+            "null"
+          ]
+        },
+        "limit": {
+          "description": "Optional page size; defaults to the full result set.",
+          "format": "uint32",
+          "minimum": 0.0,
+          "type": [
+            "integer",
+            "null"
+          ]
+        }
+      },
+      "type": "object"
+    },
     "Personality": {
       "enum": [
         "none",
@@ -5324,6 +5352,30 @@
       "title": "ExperimentalFeature/listRequest",
       "type": "object"
     },
+    {
+      "properties": {
+        "id": {
+          "$ref": "#/definitions/RequestId"
+        },
+        "method": {
+          "enum": [
+            "permissionProfile/list"
+          ],
+          "title": "PermissionProfile/listRequestMethod",
+          "type": "string"
+        },
+        "params": {
+          "$ref": "#/definitions/PermissionProfileListParams"
+        }
+      },
+      "required": [
+        "id",
+        "method",
+        "params"
+      ],
+      "title": "PermissionProfile/listRequest",
+      "type": "object"
+    },
     {
       "properties": {
         "id": {