Log full agent context window on completion

Save all context sections (system, identity, journal, conversation)
to per-agent log files for both subconscious and unconscious agents.

Co-Authored-By: ProofOfConcept <poc@bcachefs.org>

src/mind/subconscious.rs

@@ -617,6 +617,7 @@ impl Subconscious {
 
             self.agents[idx].handle = Some(tokio::spawn(async move {
                 let result = auto.run_forked_shared(&forked, &keys, &st, &recent).await;
+                super::unconscious::save_agent_log(&auto.name, &forked).await;
                 (auto, result)
             }));
         }