Add skill approval event/response (#12633)

Set the stage for skill-level permission approval in addition to
command-level.

Behind a feature flag.

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

@@ -576,6 +576,21 @@
         }
       ]
     },
+    "SkillRequestApprovalParams": {
+      "properties": {
+        "itemId": {
+          "type": "string"
+        },
+        "skillName": {
+          "type": "string"
+        }
+      },
+      "required": [
+        "itemId",
+        "skillName"
+      ],
+      "type": "object"
+    },
     "ThreadId": {
       "type": "string"
     },
@@ -737,6 +752,30 @@
       "title": "Item/tool/requestUserInputRequest",
       "type": "object"
     },
+    {
+      "properties": {
+        "id": {
+          "$ref": "#/definitions/RequestId"
+        },
+        "method": {
+          "enum": [
+            "skill/requestApproval"
+          ],
+          "title": "Skill/requestApprovalRequestMethod",
+          "type": "string"
+        },
+        "params": {
+          "$ref": "#/definitions/SkillRequestApprovalParams"
+        }
+      },
+      "required": [
+        "id",
+        "method",
+        "params"
+      ],
+      "title": "Skill/requestApprovalRequest",
+      "type": "object"
+    },
     {
       "description": "Execute a dynamic tool call on the client.",
       "properties": {