feat(ui): confirm ending a show and surface help

End-session buttons, Escape, and window close share one confirm. Help is a question-mark icon on the control panel and after the version. About opens directly. Scene editor follows the UI language.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/renderer/control/ControlApp.tsx

@@ -1958,6 +1958,22 @@ export function ControlApp() {
               </svg>
             </span>
           </Button>
+          <Button
+            variant="ghost"
+            iconOnly
+            title={t('control.helpTool')}
+            ariaLabel={t('control.helpTool')}
+            data-testid="control-help-tool"
+            onClick={() => {
+              void api.invoke(ipcChannels.windows.openInstructions, { section: 'controlPanel' }).catch((err) => {
+                console.error('[control] openInstructions failed', err);
+              });
+            }}
+          >
+            <span className={styles.iconGlyph} aria-hidden>
+              ?
+            </span>
+          </Button>
         </div>
         <div className={styles.spacer12} />
         <>
@@ -2498,9 +2514,7 @@ export function ControlApp() {
                     : t('control.showPlayers')}
                 </Button>
               ) : null}
-              <Button onClick={() => void api.invoke(ipcChannels.windows.closeMultiWindow, {})}>
-                {t('control.stopPresentation')}
-              </Button>
+              <Button onClick={() => setStopConfirmOpen(true)}>{t('control.stopPresentation')}</Button>
             </div>
           </div>
           <div className={styles.spacer10} />
@@ -2508,7 +2522,7 @@ export function ControlApp() {
           <div
             ref={previewFrameRef}
             className={styles.previewFrame}
-            title="Колесо — зум; перетаскивание СКМ/ПКМ или Space+ЛКМ — пан"
+            title={t('control.previewPanHint')}
           >
             <div
               ref={previewHostRef}
@@ -3124,9 +3138,9 @@ export function ControlApp() {
                 <Button
                   variant="primary"
                   disabled={!session?.project?.currentGraphNodeId}
-                  onClick={() => void api.invoke(ipcChannels.windows.closeMultiWindow, {})}
+                  onClick={() => setStopConfirmOpen(true)}
                 >
-                  {t('control.endPresentation')}
+                  {t('control.stopPresentation')}
                 </Button>
               </div>
             ) : null}