Capture UX: "+ New" header button + type-to-compose (two-mode board keys)

Live-pass feedback: the wide "Take a note…" bar showed through behind the
compose modal and felt redundant. Per operator choice, remove the bar and
make capture header-button + keyboard driven.

- Removed the board's inline "Take a note…" trigger bar.
- AppShell gains a "+ New" header button (next to search) — navigates to the
  board if needed, then opens the compose modal. The `c` shortcut now does
  the same (unified with newNote()).
- Type-to-compose: on the board with no card focused, any other single
  printable key opens a new note SEEDED with that key (AppShell onKeydown
  fall-through, after the reserved / c ? g shortcuts). Seed travels via
  ui.composeSeed → NoteEditor's new `initialBody` prop; caret placed at end.
- Two-mode board keyboard (BoardView): RESTING = arrows enter browse, letters
  type-to-compose; BROWSING (a card focused) = j/k move, e/x/# act, Enter
  opens, Esc exits to resting. ui.boardCardFocused tells the global handler
  to stand down while browsing so it doesn't swallow card keys.
- Updated the shortcuts help + the empty-state copy ("Hit + New — or just
  start typing").

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

frontend/src/components/AppShell.vue

@@ -1,5 +1,5 @@
 <script setup lang="ts">
-import { computed, onBeforeUnmount, onMounted, ref, watch } from "vue";
+import { computed, nextTick, onBeforeUnmount, onMounted, ref, watch } from "vue";
 import { useRoute, useRouter } from "vue-router";
 import { useSessionStore } from "../stores/session";
 import { useConfigStore } from "../stores/config";
@@ -42,18 +42,18 @@ let searchTimer: ReturnType<typeof setTimeout> | undefined;
 
 const shortcuts = [
   { label: "Command palette", keys: ["⌘/Ctrl", "K"] },
-  { label: "New note", keys: ["c"] },
+  { label: "New note (or just start typing)", keys: ["c"] },
   { label: "Search", keys: ["/"] },
   { label: "Go to Board", keys: ["g", "b"] },
   { label: "Go to Graph", keys: ["g", "g"] },
   { label: "Go to Reminders", keys: ["g", "r"] },
   { label: "Go to Timeline", keys: ["g", "t"] },
-  { label: "Move card focus", keys: ["j", "k"] },
-  { label: "Open focused card", keys: ["Enter"] },
+  { label: "Browse cards", keys: ["↑", "↓", "←", "→"] },
+  { label: "Move / open focused card", keys: ["j", "k", "Enter"] },
   { label: "Pin / archive / trash card", keys: ["#", "e", "x"] },
   { label: "Finish & close note", keys: ["⌘/Ctrl", "Enter"] },
-  { label: "Save & new (composer)", keys: ["Shift", "Enter"] },
-  { label: "Close / back to Notes", keys: ["Esc"] },
+  { label: "Save & new (composing)", keys: ["Shift", "Enter"] },
+  { label: "Stop browsing / back to Notes", keys: ["Esc"] },
   { label: "This help", keys: ["?"] },
 ];
 
@@ -70,11 +70,14 @@ function focusSearch() {
   searchInput.value?.select();
 }
 
-// `c` composes: jump to the board (which autofocuses its quick-add) or, if
-// already there, ask the board to reopen the composer.
-function compose() {
-  if (route.name !== "board") void router.push("/");
-  else ui.requestCompose();
+// New note (the "+ New" button and the `c` shortcut): ensure we're on the board,
+// then open the compose modal. Type-to-compose seeds it instead (see onKeydown).
+async function newNote() {
+  if (route.name !== "board") {
+    await router.push("/");
+    await nextTick();
+  }
+  ui.requestCompose();
 }
 
 // Global keyboard shortcuts, active only inside the authed shell. Ignored while
@@ -137,7 +140,7 @@ function onKeydown(e: KeyboardEvent) {
   }
   if (e.key === "c") {
     e.preventDefault();
-    compose();
+    void newNote();
     return;
   }
   if (e.key === "?") {
@@ -149,6 +152,13 @@ function onKeydown(e: KeyboardEvent) {
     gPending = true;
     clearTimeout(gTimer);
     gTimer = setTimeout(() => (gPending = false), 800);
+    return;
+  }
+  // Type-to-compose: any OTHER single printable key, on the board with no card
+  // focused (browse mode owns j/k/e/x/#), opens a new note seeded with that key.
+  if (route.name === "board" && !ui.boardCardFocused && e.key.length === 1 && /\S/.test(e.key)) {
+    e.preventDefault();
+    ui.requestCompose(e.key);
   }
 }
 
@@ -240,6 +250,14 @@ async function signOut() {
         </div>
 
         <div class="flex shrink-0 items-center gap-3">
+          <button
+            type="button"
+            class="inline-flex items-center gap-1 rounded-lg bg-brand px-2.5 py-1.5 text-sm font-semibold text-neutral-900 hover:brightness-95 focus:outline-none focus-visible:ring-2 focus-visible:ring-brand"
+            title="New note (or just start typing)"
+            @click="newNote"
+          >
+            <Icon name="plus" /> <span class="hidden sm:inline">New</span>
+          </button>
           <span class="hidden text-sm text-neutral-500 md:inline dark:text-neutral-400">{{
             session.user?.display_name
           }}</span>