fix(search): don't open the command palette via Cmd/Ctrl+K while typing (#1414)

The global command palette's Cmd/Ctrl+K shortcut fired even when a text
field or the code editor held focus, stealing focus mid-edit and, on
macOS, clobbering the native Ctrl+K delete-to-end-of-line. Guard the
handler with isInputFocused() so the shortcut opens search only when the
user is not typing in a field; the toolbar search icon still opens it
from anywhere. Add unit tests for the keyboard path.

frontend/src/components/GlobalCommandPalette.tsx

@@ -18,6 +18,7 @@ import {
 } from '@/components/ui/command';
 import { DialogDescription, DialogTitle } from '@/components/ui/dialog';
 import { useNodes, type Node } from '@/context/NodeContext';
+import { isInputFocused } from '@/lib/keyboard-guards';
 import { cn } from '@/lib/utils';
 import {
     useCrossNodeStackSearch,
@@ -51,6 +52,10 @@ export function GlobalCommandPaletteProvider({ children }: { children: ReactNode
                 // Let cmdk's own Ctrl+K handling take precedence when focus is already inside a palette
                 const target = e.target as HTMLElement | null;
                 if (target?.closest('[cmdk-root]')) return;
+                // Don't hijack Cmd/Ctrl+K while the user is typing in a field or the code
+                // editor: stealing focus mid-edit is surprising, and on macOS Ctrl+K is the
+                // native delete-to-end-of-line. Search still opens elsewhere, or via the icon.
+                if (isInputFocused()) return;
                 e.preventDefault();
                 setOpen(prev => !prev);
             }

frontend/src/components/__tests__/GlobalCommandPalette.test.tsx

@@ -62,6 +62,18 @@ function type(value: string) {
   fireEvent.change(screen.getByPlaceholderText('Search the app...'), { target: { value } });
 }
 
+// Focus a real text input for the duration of `run`, then always detach it.
+function withFocusedInput(run: (input: HTMLInputElement) => void) {
+  const input = document.createElement('input');
+  document.body.appendChild(input);
+  input.focus();
+  try {
+    run(input);
+  } finally {
+    document.body.removeChild(input);
+  }
+}
+
 beforeEach(() => {
   hookReturn = { hits: [], failedNodes: [], loading: false };
   nodesValue = {
@@ -208,4 +220,36 @@ describe('GlobalCommandPalette', () => {
     type('zzzz');
     expect(screen.getByText('Searching...')).toBeInTheDocument();
   });
+
+  it('opens on Ctrl+K when no field is focused', () => {
+    renderPalette();
+    fireEvent.keyDown(document.body, { key: 'k', ctrlKey: true });
+    expect(screen.getByPlaceholderText('Search the app...')).toBeInTheDocument();
+  });
+
+  it('ignores Ctrl+K while a text field is focused (no focus hijack)', () => {
+    renderPalette();
+    withFocusedInput(input => {
+      fireEvent.keyDown(input, { key: 'k', ctrlKey: true });
+      expect(screen.queryByPlaceholderText('Search the app...')).not.toBeInTheDocument();
+    });
+  });
+
+  it('ignores Cmd+K (metaKey) while a text field is focused', () => {
+    renderPalette();
+    withFocusedInput(input => {
+      fireEvent.keyDown(input, { key: 'k', metaKey: true });
+      expect(screen.queryByPlaceholderText('Search the app...')).not.toBeInTheDocument();
+    });
+  });
+
+  it('does not close the open palette when Ctrl+K is pressed inside it', () => {
+    // The [cmdk-root] early-return must run before the input-focus guard, so the
+    // app handler never toggles the palette closed while focus is in its own input.
+    renderPalette();
+    open();
+    const paletteInput = screen.getByPlaceholderText('Search the app...');
+    fireEvent.keyDown(paletteInput, { key: 'k', ctrlKey: true });
+    expect(screen.getByPlaceholderText('Search the app...')).toBeInTheDocument();
+  });
 });