keyboard: global shortcuts + ? cheat-sheet

App-shell keydown dispatcher (active only inside the authed shell):
- c        new note (jump to board / reopen composer via a ui-store signal)
- /        focus the search box
- g b/g/r  jump to Board / Graph / Reminders (two-key, 800ms window)
- ?        open a keyboard-shortcuts cheat-sheet overlay
- Esc      blur a focused field / close the cheat-sheet

Ignored while typing in an input/textarea/contenteditable (except Esc).
New stores/ui.ts carries the compose signal; QuickAdd exposes open(); the
board reopens the composer on the signal when already on the board.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01FRgehjoz7Yv8LkUfADxACm

frontend/src/views/BoardView.vue

@@ -2,14 +2,24 @@
 import { computed, onMounted, ref, watch } from "vue";
 import { useRoute } from "vue-router";
 import { useNotesStore, type Note, type NoteView } from "../stores/notes";
+import { useUiStore } from "../stores/ui";
 import QuickAdd from "../components/QuickAdd.vue";
 import NoteCard from "../components/NoteCard.vue";
 import NoteEditor from "../components/NoteEditor.vue";
 
 const notes = useNotesStore();
 const route = useRoute();
+const ui = useUiStore();
 
 const editing = ref<Note | null>(null);
+const quickAdd = ref<InstanceType<typeof QuickAdd> | null>(null);
+
+// The global `c` shortcut bumps composeTick; reopen the composer when we're
+// already on the board (a fresh navigation autofocuses it via the prop).
+watch(
+  () => ui.composeTick,
+  () => quickAdd.value?.open(),
+);
 
 function viewForRoute(name: unknown): NoteView {
   if (name === "archive") return "archived";
@@ -77,7 +87,7 @@ async function onDrop(target: Note) {
 
 <template>
   <div class="mx-auto w-full max-w-6xl px-4 py-6">
-    <QuickAdd v-if="isMainBoard" autofocus class="mb-8" />
+    <QuickAdd v-if="isMainBoard" ref="quickAdd" autofocus class="mb-8" />
 
     <div v-if="notes.loading" class="py-24 text-center text-sm text-neutral-400">Loading…</div>