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/core/src/agent/control_tests.rs

@@ -252,7 +252,7 @@ fn has_subagent_notification(history_items: &[ResponseItem]) -> bool {
             ContentItem::InputText { text } | ContentItem::OutputText { text } => {
                 SubagentNotification::matches_text(text)
             }
-            ContentItem::InputImage { .. } => false,
+            ContentItem::InputImage { .. } | ContentItem::InputAudio { .. } => false,
         })
     })
 }
@@ -267,7 +267,7 @@ fn history_contains_text(history_items: &[ResponseItem], needle: &str) -> bool {
             ContentItem::InputText { text } | ContentItem::OutputText { text } => {
                 text.contains(needle)
             }
-            ContentItem::InputImage { .. } => false,
+            ContentItem::InputImage { .. } | ContentItem::InputAudio { .. } => false,
         })
     })
 }
@@ -290,7 +290,9 @@ fn history_contains_assistant_inter_agent_communication(
                     .as_ref()
                     == Some(expected)
             }
-            ContentItem::InputText { .. } | ContentItem::InputImage { .. } => false,
+            ContentItem::InputText { .. }
+            | ContentItem::InputImage { .. }
+            | ContentItem::InputAudio { .. } => false,
         })
     })
 }