Add durable user-message queue dispatch (#37204)

## What changed

- Add a storage-neutral queue extension for listing, adding, editing, reordering, deleting, and explicitly starting queued user messages.
- Dispatch queued messages in FIFO order when a thread becomes idle after a completed turn, while leaving them queued after interruptions or failures.
- Wait for user input to be persisted before removing its queue item, and report hook rejection, task termination, and persistence failures distinctly.
- Snapshot local image and audio attachments into validated data URLs before storing them, enforce input limits, and emit `ThreadQueueChanged` events after mutations.

## Testing

- Cover queue mutations, automatic and explicit dispatch, interruption and failure behavior, hook rejection, invalid records, input limits, and local attachment snapshotting.

GitOrigin-RevId: 14f39d7c8cbaccb767a6da84b82cced0edfcb4b9

codex-rs/mcp-server/src/codex_tool_runner.rs

@@ -306,8 +306,8 @@ async fn run_codex_tool_session_inner(
                     EventMsg::SessionConfigured(_) => {
                         tracing::error!("unexpected SessionConfigured event");
                     }
-                    EventMsg::ThreadGoalUpdated(_) => {
-                        // Ignore thread goal metadata updates in MCP tool runner.
+                    EventMsg::ThreadGoalUpdated(_) | EventMsg::ThreadQueueChanged(_) => {
+                        // Ignore thread-scoped metadata updates in MCP tool runner.
                     }
                     EventMsg::McpStartupUpdate(_) | EventMsg::McpStartupComplete(_) => {
                         // Ignored in MCP tool runner.