Keep finger pan/zoom working after using the pen

After writing with the pen, fingers could no longer navigate:
- every touch was ignored for 5 s after any pen activity (and for as long
  as a hover-capable pen stayed near the screen),
- after that, a one-finger drag on a page drew ink instead of panning,
- a one-finger drag on the background did nothing while an ink tool was on.

Once a pen has been used, fingers now only pan and zoom. The 5 s session
and hover lockouts only block finger ink; touches are still rejected while
the pen is down, for palm-sized contacts and within 150 ms of pen activity.
A finger drag off the page always pans.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VsorPV3JeJRoZ1mD1pdvtL

src/lib/components/CanvasView.svelte

@@ -271,8 +271,10 @@
 		if (target.closest('.no-stage')) return;
 		const p = local(e);
 
+		// Fingers ink only when enabled and no pen has been used; otherwise they pan/zoom.
+		const fingerInks = tools.inking && settings.data.fingerDraw && !palm.penSeen;
 		if (e.pointerType === 'touch') {
-			const decision = palm.evaluate(e);
+			const decision = palm.evaluate(e, fingerInks ? 'draw' : 'navigate');
 			if (!decision.accept) return; // palm: ignore entirely
 			touches.set(e.pointerId, p);
 			if (touches.size >= 2) {
@@ -293,7 +295,7 @@
 		const wantsPan =
 			e.button === 1 ||
 			spaceDown ||
-			(e.pointerType === 'touch' && (!tools.inking || !settings.data.fingerDraw)) ||
+			(e.pointerType === 'touch' && (!fingerInks || !onPage)) ||
 			(e.pointerType === 'mouse' && e.button === 0 && !onPage && !target.closest('.ghost, .slot'));
 		if (wantsPan) {
 			if (onPage && !inEditor) doc.activeId = onPage;