Add global keyboard EventRouter and unify publish (M6, §01D)

One module owns the document keydown listener and dispatches the shortcut map
(Cmd/Ctrl+Shift+N / +K / +S / +, / Escape), platform-aware, via the single-source
focus-utils interactive-context gate. Escape and Cmd/Ctrl+S run before the gate so
save works while editing; the rest are suppressed mid-typing. Publish + its toast
move into services/snippet-actions so the button and Cmd/Ctrl+S behave identically.
Removes the ad-hoc keydown handler from App and Monaco's Cmd+S command.

src/app/components/SpecEditor.tsx

@@ -27,6 +27,7 @@ import { openModal } from '../modals/ModalCoordinator';
 import { useAppStore } from '../stores/AppStore';
 import { confirm } from '../stores/ConfirmStore';
 import { hasInlineData } from '../stores/ExtractStore';
+import { publishActiveSnippet } from '../services/snippet-actions';
 import { notify } from '../stores/NotificationStore';
 import { usePreviewStore } from '../stores/PreviewStore';
 import { selectActiveSnippet, selectShownText, useSnippetStore } from '../stores/SnippetStore';
@@ -152,18 +153,9 @@ function EditorToolbar() {
     (s) => s.activeSnippetId !== null && hasInlineData(s.draftText),
   );
 
-  const handlePublish = () => {
-    if (!useSnippetStore.getState().activeSnippetId) return;
-    useSnippetStore.getState().publish();
-    // Success confirmation (spec §03D). Per the council's toast-copy rule
-    // (docs/architecture/10 → Toast copy), the title states the action and the
-    // message adds the consequence rather than paraphrasing it.
-    notify({
-      kind: 'success',
-      title: 'Snippet published',
-      message: 'Your draft is now the published version.',
-    });
-  };
+  // Publish + its success toast live in one place (services/snippet-actions) so
+  // the button and the Cmd/Ctrl+S shortcut (EventRouter) behave identically.
+  const handlePublish = publishActiveSnippet;
 
   const handleRevert = async () => {
     const ok = await confirm({
@@ -275,10 +267,10 @@ export function SpecEditor() {
       }
     });
 
-    // Cmd/Ctrl+S publishes the current draft (spec §03D → Publish).
-    editor.addCommand(monaco.KeyMod.CtrlCmd | monaco.KeyCode.KeyS, () => {
-      if (useSnippetStore.getState().activeSnippetId) useSnippetStore.getState().publish();
-    });
+    // Cmd/Ctrl+S is owned globally by the EventRouter (docs/architecture/04 →
+    // "bind listeners in exactly one place"), which publishes before the
+    // interactive-context gate so it works while the editor has focus. Monaco
+    // binds no default for Cmd+S, so the keystroke bubbles to that one handler.
 
     return () => {
       sub.dispose();