Context bar: only show for actively-written sessions (gate on recent mtime)

A bash pane sitting in a directory that once had a claude session was
lighting up with that session's stale context. Gate the indicator on the
matched session having been written within the last 10 min, so it tracks
a live claude rather than any dormant transcript in the same dir.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/lib/layout/LeafPane.tsx

@@ -22,6 +22,12 @@ import "./LeafPane.css";
 
 const IDLE_THRESHOLD_MS = 5000;
 
+/** Only show the context indicator when the matched claude session has been
+ *  written recently — i.e. claude is actually live in (or just used in) this
+ *  pane's directory. Without this, a plain bash pane sitting in a directory
+ *  that once had a claude session lights up with that session's stale context. */
+const CONTEXT_ACTIVE_MS = 10 * 60 * 1000;
+
 /** How far past a viewport edge the cursor must travel before a release is
  *  treated as "drag pane out of window" instead of "drop on empty space
  *  inside this window". Picked so an accidental release on the OS titlebar
@@ -419,10 +425,16 @@ export default function LeafPane({ leaf }: { leaf: LeafNode }) {
   })();
 
   const matchCwd = liveCwd ?? leaf.cwd;
-  const ctx =
+  const matchedCtx =
     leaf.shellKind === "wsl" && matchCwd
       ? orch.paneContext.get(matchCwd)
       : undefined;
+  // Suppress stale matches: only surface the bar while the session is actively
+  // being written (a live claude keeps its transcript fresh).
+  const ctx =
+    matchedCtx && Date.now() - matchedCtx.lastActiveMs < CONTEXT_ACTIVE_MS
+      ? matchedCtx
+      : undefined;
 
   return (
     <div