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/SettingsModal.svelte

@@ -82,12 +82,12 @@
 			{:else if tab === 'input'}
 				<h2>Pen &amp; touch</h2>
 				<div class="row">
-					<div><div class="name">Draw with finger</div><div class="desc">When off, a single finger always pans; only pen and mouse draw.</div></div>
+					<div><div class="name">Draw with finger</div><div class="desc">When off, a single finger always pans; only pen and mouse draw. Once you use a pen, fingers only pan and zoom.</div></div>
 					<input type="checkbox" class="toggle" bind:checked={s.fingerDraw} onchange={save} />
 				</div>
 				<h3>Palm rejection</h3>
 				<div class="row">
-					<div><div class="name">Pen session lockout</div><div class="desc">Ignore touches while the pen is writing or was used in the last 5 seconds.</div></div>
+					<div><div class="name">Pen session lockout</div><div class="desc">Ignore touches while the pen is writing, and finger ink for 5 seconds after it was used.</div></div>
 					<input type="checkbox" class="toggle" bind:checked={s.palm.penSession} onchange={save} />
 				</div>
 				<div class="row">
@@ -99,7 +99,7 @@
 					<input type="checkbox" class="toggle" bind:checked={s.palm.timing} onchange={save} />
 				</div>
 				<div class="row">
-					<div><div class="name">Lock out on pen hover</div><div class="desc">Ignore touches while the pen hovers above the screen.</div></div>
+					<div><div class="name">Lock out on pen hover</div><div class="desc">Ignore finger ink while the pen hovers above the screen.</div></div>
 					<input type="checkbox" class="toggle" bind:checked={s.palm.hover} onchange={save} />
 				</div>
 			{:else}