fix(tui): prevent question tool keybindings when dialog is open

The QuestionPrompt component captures H/L keys for tab navigation,
which conflicts with typing in the command palette when opened via
Ctrl+P. This change adds a guard to skip keyboard event processing
when a dialog is open, following the established pattern used in
dialog-command.tsx.

Fixes anomalyco#8118

Co-Authored-By: Claude <[email protected]>

Author: zerone0x

packages/opencode/src/cli/cmd/tui/routes/session/question.tsx

@@ -121,6 +121,9 @@ export function QuestionPrompt(props: { request: QuestionRequest }) {
   const dialog = useDialog()
 
   useKeyboard((evt) => {
+    // Skip processing if a dialog (e.g., command palette) is open
+    if (dialog.stack.length > 0) return
+
     // When editing "Other" textarea
     if (store.editing && !confirm()) {
       if (evt.name === "escape") {