fix: restore PDF pen capture and overhaul sticky/pens/pages

Reinstall PenCaptureBinding so stylus ink hits again; keep finger Listener translucent under pinch; page-anchor sticky with drag/resize; OneNote pen slots (brush+width+color); blank-note multi-page; default side button to hold-select-text.

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

lib/editor/canvas/pen_canvas.dart

@@ -85,6 +85,8 @@ class PenCanvas extends StatefulWidget {
     this.allowFingerDrawing = false,
     this.minScale = 0.5,
     this.maxScale = 8.0,
+    this.scaleEnabled = true,
+    this.panEnabled = true,
     this.onPenDebug,
     this.thinning = kDefaultPenThinning,
     this.pressureGamma = kNaturalPressureGamma,
@@ -163,6 +165,13 @@ class PenCanvas extends StatefulWidget {
   final double minScale;
   final double maxScale;
 
+  /// When false, the canvas cannot be pinch-zoomed (sticky notes lock this so
+  /// writing isn't fighting an inner transform).
+  final bool scaleEnabled;
+
+  /// When false, one-finger pan is disabled (sticky notes often lock pan too).
+  final bool panEnabled;
+
   /// perfect_freehand pressure→width response, from `PenConfig.pressureSensitivity`.
   final double thinning;
 
@@ -804,7 +813,7 @@ class _PenCanvasState extends State<PenCanvas> {
     // governs touch/mouse: suppress pan while a single-finger / mouse stroke is
     // in progress (finger-drawing mode); a 2nd pointer cancels the stroke first
     // so a pinch re-enables pan/zoom immediately.
-    final panEnabled = _drawPointer == null;
+    final panEnabled = widget.panEnabled && _drawPointer == null;
 
     // Mirror committed strokes into the revision-tracked store (only re-mirrors
     // when the parent handed us a new list identity).
@@ -823,7 +832,7 @@ class _PenCanvasState extends State<PenCanvas> {
         minScale: widget.minScale,
         maxScale: widget.maxScale,
         panEnabled: panEnabled,
-        scaleEnabled: true,
+        scaleEnabled: widget.scaleEnabled,
         child: SizedBox(
           width: widget.pageSize.width,
           height: widget.pageSize.height,