refactor: deprecate legacy confirmation settings and enforce Policy Engine (#15626)

docs/cli/settings.md

@@ -94,7 +94,6 @@ they appear in the UI.
 | Enable Tool Output Truncation    | `tools.enableToolOutputTruncation`   | Enable truncation of large tool outputs.                                                                        | `true`  |
 | Tool Output Truncation Threshold | `tools.truncateToolOutputThreshold`  | Truncate tool output if it is larger than this many characters. Set to -1 to disable.                           | `10000` |
 | Tool Output Truncation Lines     | `tools.truncateToolOutputLines`      | The number of lines to keep when truncating tool output.                                                        | `100`   |
-| Enable Message Bus Integration   | `tools.enableMessageBusIntegration`  | Enable policy-based tool confirmation via message bus integration.                                              | `true`  |
 
 ### Security
 

docs/get-started/configuration.md

@@ -684,14 +684,6 @@ their corresponding top-level category object in your `settings.json` file.
   - **Default:** `1000`
   - **Requires restart:** Yes
 
-- **`tools.enableMessageBusIntegration`** (boolean):
-  - **Description:** Enable policy-based tool confirmation via message bus
-    integration. When enabled, tools automatically respect policy engine
-    decisions (ALLOW/DENY/ASK_USER) without requiring individual tool
-    implementations.
-  - **Default:** `true`
-  - **Requires restart:** Yes
-
 - **`tools.enableHooks`** (boolean):
   - **Description:** Enable the hooks system for intercepting and customizing
     Gemini CLI behavior. When enabled, hooks configured in settings will execute