feat(voice): implement real-time voice mode with cloud and local backends (#24174)

docs/reference/configuration.md

@@ -1691,6 +1691,32 @@ their corresponding top-level category object in your `settings.json` file.
   - **Default:** `false`
   - **Requires restart:** Yes
 
+- **`experimental.voiceMode`** (boolean):
+  - **Description:** Enable experimental voice dictation and commands (/voice,
+    /voice model).
+  - **Default:** `false`
+
+- **`experimental.voice.activationMode`** (enum):
+  - **Description:** How to trigger voice recording with the Space key.
+  - **Default:** `"push-to-talk"`
+  - **Values:** `"push-to-talk"`, `"toggle"`
+
+- **`experimental.voice.backend`** (enum):
+  - **Description:** The backend to use for voice transcription.
+  - **Default:** `"gemini-live"`
+  - **Values:** `"gemini-live"`, `"whisper"`
+
+- **`experimental.voice.whisperModel`** (enum):
+  - **Description:** The Whisper model to use for local transcription.
+  - **Default:** `"ggml-base.en.bin"`
+  - **Values:** `"ggml-tiny.en.bin"`, `"ggml-base.en.bin"`,
+    `"ggml-large-v3-turbo-q5_0.bin"`, `"ggml-large-v3-turbo-q8_0.bin"`
+
+- **`experimental.voice.stopGracePeriodMs`** (number):
+  - **Description:** How long to wait for final transcription after stopping
+    recording.
+  - **Default:** `1000`
+
 - **`experimental.adk.agentSessionNoninteractiveEnabled`** (boolean):
   - **Description:** Enable non-interactive agent sessions.
   - **Default:** `false`