Add audio variants to user input protocols (#33923)

## What changed

- Add remote and local audio variants to core and app-server user inputs, including generated JSON and TypeScript schemas.
- Preserve audio fields when converting app-server inputs and response content into thread items.
- Keep unsupported audio out of model requests, TUI rendering, text extraction, and truncated tool output, using explicit text placeholders where audio is submitted as a model input.

## Testing

- Cover app-server media conversion, unsupported-input placeholders, TUI omission, and tool-output truncation.

GitOrigin-RevId: 16152bf3af674575ce569764a8b472e032e7569d

codex-rs/app-server-protocol/src/protocol/v2/tests.rs

@@ -2545,6 +2545,12 @@ fn core_turn_item_into_thread_item_converts_supported_variants() {
                 path: PathBuf::from("local/image.png"),
                 detail: Some(ImageDetail::Original),
             },
+            CoreUserInput::Audio {
+                audio_url: "data:audio/wav;base64,AAA".to_string(),
+            },
+            CoreUserInput::LocalAudio {
+                path: PathBuf::from("local/audio.mp3"),
+            },
             CoreUserInput::Skill {
                 name: "skill-creator".to_string(),
                 path: PathBuf::from("/repo/.codex/skills/skill-creator/SKILL.md"),
@@ -2574,6 +2580,12 @@ fn core_turn_item_into_thread_item_converts_supported_variants() {
                     path: PathBuf::from("local/image.png"),
                     detail: Some(ImageDetail::Original),
                 },
+                UserInput::Audio {
+                    url: "data:audio/wav;base64,AAA".to_string(),
+                },
+                UserInput::LocalAudio {
+                    path: PathBuf::from("local/audio.mp3"),
+                },
                 UserInput::Skill {
                     name: "skill-creator".to_string(),
                     path: PathBuf::from("/repo/.codex/skills/skill-creator/SKILL.md"),
@@ -3022,7 +3034,7 @@ fn mcp_tool_call_app_context_serializes_missing_mixed_version_fields_as_null() {
 }
 
 #[test]
-fn user_input_into_core_preserves_image_detail() {
+fn user_input_into_core_preserves_media_fields() {
     assert_eq!(
         UserInput::Image {
             url: "https://example.com/image.png".to_string(),
@@ -3046,6 +3058,26 @@ fn user_input_into_core_preserves_image_detail() {
             detail: Some(ImageDetail::Original),
         }
     );
+
+    assert_eq!(
+        UserInput::Audio {
+            url: "data:audio/wav;base64,AAA".to_string(),
+        }
+        .into_core(),
+        CoreUserInput::Audio {
+            audio_url: "data:audio/wav;base64,AAA".to_string(),
+        }
+    );
+
+    assert_eq!(
+        UserInput::LocalAudio {
+            path: PathBuf::from("local/audio.mp3"),
+        }
+        .into_core(),
+        CoreUserInput::LocalAudio {
+            path: PathBuf::from("local/audio.mp3"),
+        }
+    );
 }
 
 #[test]

codex-rs/app-server-protocol/src/protocol/v2/turn.rs

@@ -308,6 +308,12 @@ pub enum UserInput {
         detail: Option<ImageDetail>,
         path: PathBuf,
     },
+    Audio {
+        url: String,
+    },
+    LocalAudio {
+        path: PathBuf,
+    },
     Skill {
         name: String,
         path: PathBuf,
@@ -333,6 +339,8 @@ impl UserInput {
                 detail,
             },
             UserInput::LocalImage { path, detail } => CoreUserInput::LocalImage { path, detail },
+            UserInput::Audio { url } => CoreUserInput::Audio { audio_url: url },
+            UserInput::LocalAudio { path } => CoreUserInput::LocalAudio { path },
             UserInput::Skill { name, path } => CoreUserInput::Skill { name, path },
             UserInput::Mention { name, path } => CoreUserInput::Mention { name, path },
         }
@@ -354,6 +362,8 @@ impl From<CoreUserInput> for UserInput {
                 detail,
             },
             CoreUserInput::LocalImage { path, detail } => UserInput::LocalImage { path, detail },
+            CoreUserInput::Audio { audio_url } => UserInput::Audio { url: audio_url },
+            CoreUserInput::LocalAudio { path } => UserInput::LocalAudio { path },
             CoreUserInput::Skill { name, path } => UserInput::Skill { name, path },
             CoreUserInput::Mention { name, path } => UserInput::Mention { name, path },
             _ => unreachable!("unsupported user input variant"),
@@ -367,6 +377,8 @@ impl UserInput {
             UserInput::Text { text, .. } => text.chars().count(),
             UserInput::Image { .. }
             | UserInput::LocalImage { .. }
+            | UserInput::Audio { .. }
+            | UserInput::LocalAudio { .. }
             | UserInput::Skill { .. }
             | UserInput::Mention { .. } => 0,
         }