add TERMINFO env for top/ncurses, tighten output flush

top fails with "Error opening terminal: xterm-256color" because the
PTY child can't find terminfo. Set TERMINFO=/usr/share/terminfo
explicitly in the pane environment.

Output flush changed from 16ms Timer to Duration.zero (next event
loop turn) for tighter batching of escape sequences.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

.pql/pql-plan.json

@@ -1,5 +1,5 @@
 {
-  "exported_at": "2026-05-01T10:01:22Z",
+  "exported_at": "2026-05-01T10:08:01Z",
   "decisions": [
     {
       "id": "D-1",

lib/builtin/claude/src/claude_pane.dart

@@ -186,11 +186,13 @@ class _ClaudePaneState extends State<ClaudePane> {
           final b64 = e.data['bytes_b64'];
           if (b64 is String) {
             _outputBuf.write(utf8.decode(base64Decode(b64), allowMalformed: true));
-            // Throttle writes to ~60fps. Multiple PTY reads within a
-            // 16ms window are batched into one terminal.write() call,
-            // preventing split escape sequences from rendering as
-            // garbage between frames.
-            _flushTimer ??= Timer(const Duration(milliseconds: 16), _flushOutput);
+            // Batch all output from the current event loop turn into one
+            // terminal.write() call. scheduleMicrotask runs after all
+            // pending events but before the next frame, so split escape
+            // sequences within the same event batch are reunited.
+            if (_flushTimer == null) {
+              _flushTimer = Timer(Duration.zero, _flushOutput);
+            }
           }
         case 'pane.exit':
           if (widget.isPrimary) {

lib/src/panes/registry.dart

@@ -56,6 +56,7 @@ class PaneRegistry {
       'COLORTERM': 'truecolor',
       'LANG': 'en_US.UTF-8',
       'LC_ALL': 'en_US.UTF-8',
+      'TERMINFO': '/usr/share/terminfo',
       if (env != null) ...env,
     };