0.16.1: welcome screen arrow-key navigation

Up/Down arrow keys now move focus through the recents list in the
welcome dialog; Home/End jump to the first/last entry. Tab / Enter
/ Space behaviour is untouched — arrows are additive. Covered by
two UI tests (arrow roundtrip + Home/End) that poll for the async
IDB load instead of a fixed delay.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

src/components/WelcomeDialog.vue

@@ -80,6 +80,32 @@ function openProject(p: StoredProject) {
   emit('update:modelValue', false)
 }
 
+/** Move focus through the recents list using the arrow keys. Keeps
+ *  Tab working as usual — arrow nav is just a more natural shortcut
+ *  for picking from a list. */
+function focusRecent(index: number) {
+  const list = recentRefs.value
+  if (!list.length) return
+  const clamped = Math.max(0, Math.min(index, list.length - 1))
+  list[clamped]?.focus()
+}
+
+function onRecentKeyDown(e: KeyboardEvent, index: number) {
+  if (e.key === 'ArrowDown') {
+    e.preventDefault()
+    focusRecent(index + 1)
+  } else if (e.key === 'ArrowUp') {
+    e.preventDefault()
+    focusRecent(index - 1)
+  } else if (e.key === 'Home') {
+    e.preventDefault()
+    focusRecent(0)
+  } else if (e.key === 'End') {
+    e.preventDefault()
+    focusRecent(recentRefs.value.length - 1)
+  }
+}
+
 async function removeProject(e: MouseEvent, p: StoredProject) {
   e.stopPropagation()
   const ok = await confirmDialog({
@@ -150,6 +176,7 @@ watch(
                 @click="openProject(p)"
                 @keydown.enter.prevent="openProject(p)"
                 @keydown.space.prevent="openProject(p)"
+                @keydown="onRecentKeyDown($event, i)"
               >
                 <div class="thumb">
                   <img v-if="p.thumbnail" :src="p.thumbnail" alt="" />