feat: unified shell, diagnostics pack, native Office, sticky board

Make Surface remote debugging and classroom workflows viable: always-on
structured logs with one-click zip export, a single AppShell chrome,
OOXML PPTX/DOCX annotation without LibreOffice, and a first-class sticky
board. Also drop spike/legacy ink widgets and tighten pen feel
(predictor, PenInfoHistory, page-tile layer).

Co-authored-by: Cursor <cursoragent@cursor.com>

lib/editor/input/diagnostic_logger.dart

@@ -1,90 +1,38 @@
 // lib/editor/input/diagnostic_logger.dart
 //
-// On-device input diagnostics. When the user manually enables the diagnostic
-// (the toolbar toggle), every native pen event (raw button/flag/tilt fields)
-// and every zoom frame is emitted through the standard `dart:developer` log
-// channel (name 'badnote.input') — capturable via `flutter run`, DevTools, or
-// any log tool — AND mirrored to a text file as a fallback for the packaged
-// GUI build, which has no attached console. Disabled by default (no overhead).
+// Compatibility facade over [BadNoteLog] + [PenEventRing]. The PDF editor's
+// toolbar toggle still calls start/stop; globally, [BadNoteLog.start] runs at
+// app launch so packaged builds always have a session file.
 
 import 'dart:async';
-import 'dart:developer' as developer;
-import 'dart:io';
 
-import 'package:path_provider/path_provider.dart';
+import '../../diagnostics/badnote_log.dart';
 
 class DiagnosticLogger {
   DiagnosticLogger._();
   static final DiagnosticLogger instance = DiagnosticLogger._();
 
-  final List<String> _buffer = <String>[];
-  File? _file;
-  Timer? _timer;
-  int _epochMs = 0;
+  bool _verbose = false;
+  bool get isActive => _verbose || BadNoteLog.instance.path != null;
 
-  bool _active = false;
-  bool get isActive => _active;
+  /// Absolute path of the structured session log (preferred), else null.
+  String? get path => BadNoteLog.instance.path;
 
-  /// Absolute path of the current log file (shown in the overlay), or null.
-  String? path;
-
-  /// Begin a session. Enables the `dart:developer` log channel immediately and
-  /// opens the fallback file (best-effort). Safe to call repeatedly.
+  /// Begin a verbose input session (also ensures the global log is running).
   Future<void> start() async {
-    if (_active) return;
-    _active = true; // developer.log works even if the file can't be opened
-    _epochMs = DateTime.now().millisecondsSinceEpoch;
-    developer.log('--- session start ${DateTime.now().toIso8601String()} ---',
-        name: 'badnote.input');
-    try {
-      Directory dir;
-      try {
-        dir = await getApplicationDocumentsDirectory();
-      } catch (_) {
-        dir = await getTemporaryDirectory();
-      }
-      final file = File('${dir.path}${Platform.pathSeparator}badnote_input_log.txt');
-      await file.writeAsString(
-        '# BadNote input diagnostic log\n'
-        '# started ${DateTime.now().toIso8601String()}\n'
-        '# columns: <ms> <kind> <fields...>\n',
-        flush: true,
-      );
-      _file = file;
-      path = file.path;
-      _buffer.clear();
-      _timer = Timer.periodic(const Duration(seconds: 1), (_) => _flush());
-    } catch (_) {
-      // File is a fallback; never break the app over it.
-    }
+    _verbose = true;
+    await BadNoteLog.instance.start();
+    BadNoteLog.instance.info(LogSubsystem.diag, 'verbose_input_on');
   }
 
-  /// Emit one diagnostic line through the standard log channel and the file.
   void log(String line) {
-    if (!_active) return;
-    developer.log(line, name: 'badnote.input');
-    if (_file == null) return;
-    final t = DateTime.now().millisecondsSinceEpoch - _epochMs;
-    _buffer.add('$t $line');
-    if (_buffer.length >= 1000) _flush();
+    BadNoteLog.instance.debug(LogSubsystem.penNative, line);
   }
 
-  Future<void> _flush() async {
-    final file = _file;
-    if (file == null || _buffer.isEmpty) return;
-    final chunk = '${_buffer.join('\n')}\n';
-    _buffer.clear();
-    try {
-      await file.writeAsString(chunk, mode: FileMode.append, flush: true);
-    } catch (_) {}
-  }
-
-  /// Flush and stop. The file remains on disk for retrieval.
   Future<void> stop() async {
-    if (!_active) return;
-    _active = false;
-    _timer?.cancel();
-    _timer = null;
-    await _flush();
+    if (!_verbose) return;
+    _verbose = false;
+    BadNoteLog.instance.info(LogSubsystem.diag, 'verbose_input_off');
+    await BadNoteLog.instance.flush();
   }
 }