agent stats: track tool calls by type with EWMA, add Stats pane

- RunStats now includes tool_calls_by_type HashMap
- AutoAgent tracks runs, last_stats, and EWMA for tool calls/failures
- Removed duplicate stats fields from individual agent structs
- Fixed provenance to use bare agent name (no "agent:" prefix)
- Subconscious screen now displays both agent types consistently
- Added Stats pane showing tool call breakdown sorted by count

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

src/mind/subconscious.rs

@@ -294,6 +294,7 @@ pub struct SubconsciousSnapshot {
     pub enabled: bool,
     pub current_phase: String,
     pub turn: usize,
+    pub runs: usize,
     pub last_run_secs_ago: Option<f64>,
     /// Shared handle to the forked agent — UI locks to read entries.
     pub forked_agent: Option<Arc<crate::agent::Agent>>,
@@ -303,6 +304,9 @@ pub struct SubconsciousSnapshot {
     pub state: std::collections::BTreeMap<String, String>,
     /// Recent store activity for this agent: (key, timestamp), newest first.
     pub history: Vec<(String, i64)>,
+    pub last_stats: Option<crate::agent::oneshot::RunStats>,
+    pub tool_calls_ewma: f64,
+    pub tool_failures_ewma: f64,
 }
 
 struct SubconsciousAgent {
@@ -367,11 +371,15 @@ impl SubconsciousAgent {
             enabled: self.auto.enabled,
             current_phase: self.auto.current_phase.clone(),
             turn: self.auto.turn,
+            runs: self.auto.runs,
             last_run_secs_ago: self.last_run.map(|t| t.elapsed().as_secs_f64()),
             forked_agent: self.forked_agent.clone(),
             fork_point: self.fork_point,
             state: state.clone(),
             history,
+            last_stats: self.auto.last_stats.clone(),
+            tool_calls_ewma: self.auto.tool_calls_ewma,
+            tool_failures_ewma: self.auto.tool_failures_ewma,
         }
     }
 }
@@ -614,7 +622,8 @@ impl Subconscious {
 
             self.agents[idx].handle = Some(tokio::spawn(async move {
                 let result = auto.run_forked_shared(&forked, &keys, &st, &recent).await;
-                crate::agent::oneshot::save_agent_log(&auto.name, &forked).await;
+                let stats = crate::agent::oneshot::save_agent_log(&auto.name, &forked).await;
+                auto.update_stats(stats);
                 (auto, result)
             }));
         }