wire thalamus idle state into consciousness binary

The consciousness binary now has its own idle state machine,
fed directly by TUI events:
- Key press → user_activity()
- Turn complete → response_activity()
- Render tick → decay_ewma(), snapshot to TUI

F5 thalamus screen shows presence/activity from the in-process
state instead of shelling out to poc-daemon status. No tmux
pane scraping, no socket RPC — the binary IS the presence.

Co-Developed-By: Kent Overstreet <kent.overstreet@linux.dev>

src/bin/consciousness.rs

@@ -810,6 +810,10 @@ async fn run(cli: cli::CliArgs) -> Result<()> {
     channel_supervisor.load_config();
     channel_supervisor.ensure_running();
 
+    // Initialize idle state machine
+    let mut idle_state = poc_memory::thalamus::idle::State::new();
+    idle_state.load();
+
     // Create UI channel
     let (ui_tx, mut ui_rx) = ui_channel::channel();
 
@@ -935,6 +939,7 @@ async fn run(cli: cli::CliArgs) -> Result<()> {
                             continue;
                         }
                         app.handle_key(key);
+                        idle_state.user_activity();
                         dirty = true;
                     }
                     Some(Ok(Event::Mouse(mouse))) => {
@@ -961,16 +966,20 @@ async fn run(cli: cli::CliArgs) -> Result<()> {
             // Turn completed in background task
             Some((result, target)) = turn_rx.recv() => {
                 session.handle_turn_result(result, target).await;
+                idle_state.response_activity();
                 dirty = true;
             }
 
-            // Render tick
+            // Render tick — update periodic state
             _ = render_interval.tick() => {
                 let new_count = session.process_tracker.list().await.len() as u32;
                 if new_count != app.running_processes {
                     app.running_processes = new_count;
                     dirty = true;
                 }
+                // Update idle state for F5 screen
+                idle_state.decay_ewma();
+                app.update_idle(&idle_state);
             }
 
             // DMN timer (only when no turn is running)