organize: fine-grained agent logging + cluster size cap

Add progress callback to run_one_agent and run_and_apply so callers
can see: prompt size, node list, LLM call timing, parsed action
count, and per-action applied/skipped status. Daemon writes these
to the persistent event log via log_event.

Cap organize cluster to 20 nodes - 126 nodes produced a 682KB
prompt that timed out every time. Agent has tools to explore
further if needed. Restore general query for production runs.

poc-memory/src/agents/defs.rs

@@ -184,6 +184,11 @@ fn resolve(
             }
             cluster.sort_by(|a, b| a.0.cmp(&b.0));
 
+            // Cap cluster size — agent has tools to explore more if needed
+            if cluster.len() > 20 {
+                cluster.truncate(20);
+            }
+
             // Similarity pairs
             let pairs = crate::similarity::pairwise_similar(&cluster, 0.4);