Unconscious agents: persistent AutoAgent, shared Agent Arc for UI

- AutoAgent stored on UnconsciousAgent, swapped out for runs, restored
  on completion (same pattern as subconscious agents)
- Agent Arc created before spawn and stored on UnconsciousAgent so
  the TUI can lock it to read conversation context live
- run_shared() method on AutoAgent for running with a pre-created Agent
- Default tools: memory_tools (not memory_and_journal_tools)
- trigger/spawn_agent made async for Agent::new()

Co-Authored-By: Proof of Concept <poc@bcachefs.org>

src/user/mod.rs

@@ -384,7 +384,7 @@ async fn run(
                 let mut unc = mind.unconscious.lock().await;
                 for name in &toggles {
                     if sub.toggle(name).is_none() {
-                        unc.toggle(name);
+                        unc.toggle(name).await;
                     }
                 }
             }