fix(canvas): block invalid video duration confirmation

.project-docs/30-worklog/tasks/20260818-video-duration-client-a7c42f.md

@@ -29,6 +29,8 @@
 - The confirmation card now filters enabled server-provided video durations to the inclusive 2-6 second client boundary.
 - A legacy Quote whose selected duration is outside that boundary renders an explicit disabled `请选择时长` placeholder instead of visually selecting one allowed value while retaining a different hidden draft value.
 - Selecting 6 seconds updates the controlled draft, survives the debounced server re-quote, and is used by final confirmation.
+- Final-review P1 follow-up: a video Quote with `null`, an out-of-range duration, a disabled duration, or a duration absent from the filtered server options now disables the confirmation button and is rejected again inside the shared `handleConfirm` path used by direct, quick-reply, and text confirmation.
+- Only an explicit allowed selection followed by a successful server re-quote re-enables confirmation.
 - Existing request seams were verified: Renderer sends `durationSeconds: 6`, and the Main cloud adapter sends `duration_seconds: 6` to Works Square.
 
 ## Verification
@@ -40,6 +42,9 @@
 - `corepack pnpm exec eslint src/pages/ImageCanvas/index.tsx tests/unit/image-canvas-page.test.tsx tests/unit/works-square-design-workspace.test.ts` — passed with no output.
 - `corepack pnpm run build:vite` — passed for Renderer, Electron Main, and Preload; only the existing dynamic-import and chunk-size warnings were reported.
 - `git diff --check` — passed; Git reported only the repository's LF-to-CRLF checkout warning.
+- Final-review P1 red test: the legacy 10-second Quote initially left `确认并开始生成` enabled.
+- Final-review P1 focused regression: legacy 10-second initial state disables confirmation and text confirmation sends no request; selecting 6 seconds, completing re-quote, and confirming sends 6 — passed.
+- Post-P1 focused suite: 3 files / 92 tests passed; typecheck and scoped ESLint passed; Renderer/Main/Preload `build:vite` passed with the same existing warnings.
 
 ## Follow-ups
 

src/pages/ImageCanvas/index.tsx

@@ -268,6 +268,20 @@ type EditableGenerationParameters = Partial<Pick<
 const MIN_VIDEO_DURATION_SECONDS = 2;
 const MAX_VIDEO_DURATION_SECONDS = 6;
 
+function hasSelectableVideoDuration(
+  quote: DesignGenerationQuote,
+  parameters: DesignGenerationParameters,
+): boolean {
+  if (quote.medium !== 'video') return true;
+  const durationSeconds = parameters.durationSeconds;
+  return durationSeconds !== null
+    && durationSeconds >= MIN_VIDEO_DURATION_SECONDS
+    && durationSeconds <= MAX_VIDEO_DURATION_SECONDS
+    && quote.generationOptions.durations.some((option) => (
+      !option.disabled && option.value === durationSeconds
+    ));
+}
+
 function quoteDraftFromQuote(quote: DesignGenerationQuote): GenerationQuoteDraft {
   return {
     quoteId: quote.quoteId,
@@ -740,6 +754,10 @@ function QuoteCard({
   const selectedDuration = availableDurations.some(
     (option) => option.value === draft.generationParameters.durationSeconds,
   ) ? String(draft.generationParameters.durationSeconds) : '';
+  const durationSelectionValid = hasSelectableVideoDuration(
+    quote,
+    draft.generationParameters,
+  );
   const updateParameters = (next: EditableGenerationParameters) => {
     onDraftChange({
       ...draft,
@@ -867,7 +885,7 @@ function QuoteCard({
           size="sm"
           className="h-8 rounded-full bg-brand px-3 text-xs font-semibold text-primary-foreground"
           onClick={onConfirm}
-          disabled={busy || dirty || repricing}
+          disabled={busy || dirty || repricing || !durationSelectionValid}
         >
           {busy || repricing
             ? <Loader2 className="mr-1.5 h-3.5 w-3.5 animate-spin" />
@@ -1153,6 +1171,7 @@ export function ImageCanvas() {
     setQuoteDirty(true);
     setRepricingQuoteId(quote.quoteId);
     setQuoteUpdateError(null);
+    setActionError(null);
     quoteDraftVersionRef.current += 1;
     const version = quoteDraftVersionRef.current;
     if (quoteRepriceTimerRef.current !== null) clearTimeout(quoteRepriceTimerRef.current);
@@ -1189,6 +1208,11 @@ export function ImageCanvas() {
       setActionError('当前报价正在更新，请等待重新报价完成后再确认。');
       return;
     }
+    if (!quote || quote.quoteId !== quoteId
+      || !hasSelectableVideoDuration(quote, draft.generationParameters)) {
+      setActionError('请选择 2 至 6 秒的视频时长，等待重新报价完成后再确认。');
+      return;
+    }
     const requestedWorkspaceId = workspace.workspaceId;
     const requestedConversationId = conversation.conversationId;
     setConfirmingQuoteId(quoteId);

tests/unit/image-canvas-page.test.tsx

@@ -544,6 +544,15 @@ describe('ImageCanvas Workspace-first design experience', () => {
     expect(durationSelect).toHaveValue('');
     expect(within(durationSelect).getAllByRole('option').map((option) => option.getAttribute('value')))
       .toEqual(['', '2', '6']);
+    expect(screen.getByRole('button', { name: '确认并开始生成' })).toBeDisabled();
+
+    fireEvent.change(screen.getByLabelText('设计需求'), {
+      target: { value: '确认生成' },
+    });
+    fireEvent.click(screen.getByRole('button', { name: '发送给设计 Agent' }));
+
+    expect(confirmImageWorkspaceGenerationMock).not.toHaveBeenCalled();
+    expect(await screen.findByRole('alert')).toHaveTextContent('请选择 2 至 6 秒的视频时长');
 
     fireEvent.change(durationSelect, { target: { value: '6' } });