M7: editor keyboard + one-click card toolbars (live-pass fixes)

From the unified-editor live pass (task 1922):

- Esc now returns to the base Notes board from any view (AppShell); an open editor consumes Esc first (its handler stops propagation) so it closes before navigating.

- Ctrl/Cmd+Enter = finish & close in BOTH frames — it already closed the modal editor; now it also commits+collapses the board composer (matches the email/chat 'send' convention). Shift+Enter still saves & starts a new note.

- Fix: the inline composer committed on document mousedown, collapsing and shifting the board before a click landed — so clicking another card's pin/archive/trash took two clicks. Commit on click (bubble phase) instead; the target's action fires first, then the composer closes.

Pure frontend.

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

@@ -36,9 +36,9 @@ const shortcuts = [
   { label: "Move card focus", keys: ["j", "k"] },
   { label: "Open focused card", keys: ["Enter"] },
   { label: "Pin / archive / trash card", keys: ["#", "e", "x"] },
-  { label: "Save & close (editor)", keys: ["⌘/Ctrl", "Enter"] },
+  { label: "Finish & close note", keys: ["⌘/Ctrl", "Enter"] },
   { label: "Save & new (composer)", keys: ["Shift", "Enter"] },
-  { label: "Dismiss / close", keys: ["Esc"] },
+  { label: "Close / back to Notes", keys: ["Esc"] },
   { label: "This help", keys: ["?"] },
 ];
 
@@ -84,6 +84,12 @@ function onKeydown(e: KeyboardEvent) {
     drawer.value = false;
     return;
   }
+  // Esc with nothing open = back to the base Notes board. (An open editor gets Esc
+  // first via its own handler, which stops propagation so it doesn't also navigate.)
+  if (e.key === "Escape") {
+    if (route.name !== "board") void router.push("/");
+    return;
+  }
   if (e.metaKey || e.ctrlKey || e.altKey) return;
   if (gPending) {
     gPending = false;