Make the agents overview an interactive task dashboard (#39112)

## What changed

- Let users start tasks, open root sessions, rename tasks, and stop active work directly from the agents overview.
- Show details for the selected task on wide terminals and limit the overview to root sessions while still reflecting background activity.
- Preserve draft input and pending server requests when switching sessions so running roots and their subagents can continue in the background.
- Apply the selected project's working directory when dispatching from project grouping, including remote workspaces.

## Testing

- Expand overview rendering and interaction coverage for root filtering, dispatch, search, selection, renaming, and responsive input.
- Cover switching away from roots with running subagents and retaining background server requests.

GitOrigin-RevId: b7b0d33b7ecc077498efb756a0ad2fd425158b17

codex-rs/tui/src/app_event.rs

@@ -195,13 +195,31 @@ pub(crate) enum TranscriptExportDestination {
 #[allow(clippy::large_enum_variant)]
 #[derive(Debug)]
 pub(crate) enum AppEvent {
-    /// Open the daemon-wide overview of loaded root sessions and their subagents.
+    /// Open the daemon-wide overview of loaded root sessions.
     OpenAgentsOverview,
     /// Update the daemon-wide overview after a background thread listing finishes.
     AgentsOverviewThreadsLoaded {
         request_id: Uuid,
         result: Result<Vec<Thread>, String>,
     },
+    /// Switch to a root session selected from the shared dashboard.
+    SelectAgentsOverviewThread {
+        thread_id: ThreadId,
+    },
+    /// Start a background task directly from the shared dashboard.
+    DispatchAgentsOverviewTask {
+        prompt: String,
+        cwd: Option<AbsolutePathBuf>,
+    },
+    /// Rename a task directly from the shared dashboard.
+    RenameAgentsOverviewThread {
+        thread_id: ThreadId,
+        name: String,
+    },
+    /// Interrupt a task directly from the shared dashboard.
+    StopAgentsOverviewThread {
+        thread_id: ThreadId,
+    },
     /// Open the agent picker for switching active threads.
     OpenAgentPicker,
     /// Merge a completed root-scoped agent-picker refresh without blocking terminal input.