agent ctx-badge: seed Bus::last_usage from latest turn_stats row on startup

hive-ag3nt/src/turn_stats.rs

@@ -156,6 +156,34 @@ impl TurnStats {
             tracing::warn!(error = ?e, "turn_stats: insert failed");
         }
     }
+
+    /// Token counts from the most recently inserted row, if any. Lets
+    /// the harness seed `Bus::last_usage` on startup so the per-agent
+    /// web UI's `ctx-badge` paints with real numbers on cold load
+    /// instead of waiting for the next `TokenUsageChanged` SSE event.
+    /// Best-effort: any sqlite error returns `None` and the caller
+    /// falls back to the empty state.
+    #[must_use]
+    pub fn last_usage(&self) -> Option<crate::events::TokenUsage> {
+        let conn = self.inner.lock().unwrap();
+        conn.query_row(
+            "SELECT input_tokens, output_tokens,
+                    cache_read_input_tokens, cache_creation_input_tokens
+             FROM turn_stats
+             ORDER BY started_at DESC
+             LIMIT 1",
+            [],
+            |row| {
+                Ok(crate::events::TokenUsage {
+                    input_tokens: u64::try_from(row.get::<_, i64>(0)?).unwrap_or(0),
+                    output_tokens: u64::try_from(row.get::<_, i64>(1)?).unwrap_or(0),
+                    cache_read_input_tokens: u64::try_from(row.get::<_, i64>(2)?).unwrap_or(0),
+                    cache_creation_input_tokens: u64::try_from(row.get::<_, i64>(3)?).unwrap_or(0),
+                })
+            },
+        )
+        .ok()
+    }
 }
 
 fn default_path() -> PathBuf {