PM-5573: Adjust active challenge timeline when switching AI only and AI gating

src/apps/work/src/pages/challenges/ChallengeEditorPage/README.md

@@ -50,7 +50,7 @@ The form uses `challengeBasicInfoSchema` from `src/apps/work/src/lib/schemas/cha
 - `skills`: required unless billing account is listed in `SKILLS_OPTIONAL_BILLING_ACCOUNT_IDS`.
 - `reviewer`: optional for task challenges.
 - `reviewers`: when using `Save as Draft` from `NEW` status, non-task/non-marathon challenges must include reviewer coverage for configured review phases. If required phases are configured, each phase must have at least one member reviewer with a scorecard. The Screening and Checkpoint Screening configurations and scorecards remain required, but their Screener member assignments may be left empty until after launch. Design `Challenge` reviewers additionally leave the Checkpoint Review, Review, and Approval member assignments optional because the selected copilot is assigned to those private phases during save; other closed manual reviewer assignments remain required.
-- `AI review configuration`: templates and manual configs autosave separately once valid, switching a template-backed config to manual mode keeps its copied settings but clears the template link on save, and the AI tab becomes read-only after the challenge has submissions.
+- `AI review configuration`: templates and manual configs autosave separately once valid, switching a template-backed config to manual mode keeps its copied settings but clears the template link on save, and the AI tab becomes read-only after the challenge has submissions. The only exception is the review mode: it can still switch between AI_GATING and AI_ONLY (for manual and template configs) until a review phase (AI Screening, AI Review, Review, ...) starts. When an active challenge's mode no longer matches its timeline, the editor saves the reviewers right away so challenge-api moves the challenge to the matching timeline (AI Review and Approval for AI_ONLY, AI Screening and the review phases for AI_GATING), then loads the new phases into Timeline & Schedule.
 
 ## Autosave Behavior
 

src/apps/work/src/pages/challenges/ChallengeEditorPage/components/ReviewersField/AiReviewTab.spec.tsx

@@ -585,4 +585,149 @@ describe('AiReviewTab review mode options', () => {
         )
             .toBe(true)
     })
+
+    describe('with submissions', () => {
+        const lockedWorkflows = [
+            {
+                id: 'config-workflow-1',
+                isGating: false,
+                weightPercent: 100,
+                workflowId: 'workflow-1',
+            },
+        ]
+
+        /**
+         * Finds the Review Mode select, whose label also wraps the mode description.
+         */
+        async function findReviewModeSelect(): Promise<HTMLSelectElement> {
+            return (await screen.findByRole('option', { name: 'AI_ONLY' }))
+                .closest('select') as HTMLSelectElement
+        }
+
+        beforeEach(() => {
+            mockedFetchWorkflows.mockResolvedValue([
+                {
+                    id: 'workflow-1',
+                    name: 'Workflow 1',
+                },
+            ])
+            mockedUpdateAiReviewConfig.mockImplementation(async (_configId, input) => ({
+                ...baseConfiguration,
+                ...input,
+                id: 'config-1',
+            }))
+        })
+
+        it('keeps only the review mode editable until the review phase starts', async () => {
+            jest.useFakeTimers()
+            mockedFetchAiReviewConfigByChallenge.mockResolvedValueOnce({
+                ...baseConfiguration,
+                mode: 'AI_ONLY',
+                workflows: lockedWorkflows,
+            })
+
+            render(
+                <AiReviewTab
+                    canSwitchReviewMode
+                    challengeId='challenge-1'
+                    hasSubmissions
+                    reviewers={persistedAiReviewers}
+                />,
+            )
+
+            const reviewModeSelect = await findReviewModeSelect()
+
+            expect(reviewModeSelect.disabled)
+                .toBe(false)
+            expect((screen.getByRole('slider') as HTMLInputElement).disabled)
+                .toBe(true)
+            expect((screen.getByLabelText('AI Workflow') as HTMLSelectElement).disabled)
+                .toBe(true)
+            expect(screen.queryByRole('button', { name: 'Remove AI config' }))
+                .toBeNull()
+            expect(screen.getByText(/You can still switch the review mode/)).not.toBeNull()
+
+            fireEvent.change(reviewModeSelect, {
+                target: {
+                    value: 'AI_GATING',
+                },
+            })
+
+            await act(async () => {
+                jest.advanceTimersByTime(1600)
+            })
+
+            await waitFor(() => {
+                expect(mockedUpdateAiReviewConfig)
+                    .toHaveBeenCalledWith(
+                        'config-1',
+                        expect.objectContaining({
+                            minPassingThreshold: 75,
+                            mode: 'AI_GATING',
+                        }),
+                    )
+            })
+        })
+
+        it('lets template configs switch the review mode until the review phase starts', async () => {
+            jest.useFakeTimers()
+            mockedFetchAiReviewTemplates.mockResolvedValue([])
+            mockedFetchAiReviewConfigByChallenge.mockResolvedValueOnce({
+                ...baseConfiguration,
+                templateId: 'template-1',
+                workflows: lockedWorkflows,
+            })
+
+            render(
+                <AiReviewTab
+                    canSwitchReviewMode
+                    challengeId='challenge-1'
+                    hasSubmissions
+                    reviewers={persistedAiReviewers}
+                />,
+            )
+
+            fireEvent.change(await findReviewModeSelect(), {
+                target: {
+                    value: 'AI_ONLY',
+                },
+            })
+
+            await act(async () => {
+                jest.advanceTimersByTime(1600)
+            })
+
+            await waitFor(() => {
+                expect(mockedUpdateAiReviewConfig)
+                    .toHaveBeenCalledWith(
+                        'config-1',
+                        expect.objectContaining({
+                            mode: 'AI_ONLY',
+                            templateId: 'template-1',
+                        }),
+                    )
+            })
+        })
+
+        it('locks the review mode once the review phase has started', async () => {
+            mockedFetchAiReviewConfigByChallenge.mockResolvedValueOnce({
+                ...baseConfiguration,
+                workflows: lockedWorkflows,
+            })
+
+            render(
+                <AiReviewTab
+                    canSwitchReviewMode={false}
+                    challengeId='challenge-1'
+                    hasSubmissions
+                    reviewers={persistedAiReviewers}
+                />,
+            )
+
+            expect((await findReviewModeSelect()).disabled)
+                .toBe(true)
+            expect(screen.queryByText(/You can still switch the review mode/))
+                .toBeNull()
+        })
+    })
 })

src/apps/work/src/pages/challenges/ChallengeEditorPage/components/ReviewersField/AiReviewTab.tsx

@@ -53,6 +53,11 @@ export interface AiReviewConfigSaveController {
 }
 
 interface AiReviewTabProps {
+    /**
+     * Keeps the review mode (AI_GATING / AI_ONLY) editable while `hasSubmissions` locks the
+     * rest of the configuration. The parent sets it until the challenge's review phase starts.
+     */
+    canSwitchReviewMode?: boolean
     challengeId?: string
     hasSubmissions?: boolean
     onConfigRemoved?: () => Promise<void> | void
@@ -89,6 +94,8 @@ interface ManualWorkflowEditorProps {
 }
 
 interface ReviewSettingsProps {
+    /** Keeps the review mode select enabled when `readOnly` locks the other settings. */
+    canChangeMode?: boolean
     configuration: AiReviewConfigurationDraft
     onUpdate: <K extends keyof AiReviewConfigurationDraft>(
         field: K,
@@ -418,7 +425,7 @@ const ReviewSettings: FC<ReviewSettingsProps> = (
                 <label className={styles.fieldGroup}>
                     <span>Review Mode</span>
                     <select
-                        disabled={props.readOnly}
+                        disabled={props.readOnly && props.canChangeMode !== true}
                         onChange={handleModeChange}
                         value={mode}
                     >
@@ -494,6 +501,9 @@ export const AiReviewTab: FC<AiReviewTabProps> = (
     const normalizedChallengeId = normalizeReviewerText(props.challengeId)
     const onConfigRemoved = props.onConfigRemoved
     const readOnly = props.hasSubmissions === true
+    // A locked configuration can still switch its review mode until the review phase starts.
+    const canSwitchReviewModeOnly = readOnly && props.canSwitchReviewMode === true
+    const isAutosaveLocked = readOnly && !canSwitchReviewModeOnly
     const onConfigPersisted = props.onConfigPersisted
     const onConfigSaveControllerReady = props.onConfigSaveControllerReady
     const onSelectedModeChange = props.onSelectedModeChange
@@ -1041,7 +1051,7 @@ export const AiReviewTab: FC<AiReviewTabProps> = (
     }, [configurationMode, selectedTrackName, selectedTypeName])
 
     const persistConfiguration = useCallback(async (): Promise<void> => {
-        if (!normalizedConfiguration || readOnly || validationErrors.length > 0) {
+        if (!normalizedConfiguration || isAutosaveLocked || validationErrors.length > 0) {
             return
         }
 
@@ -1075,7 +1085,7 @@ export const AiReviewTab: FC<AiReviewTabProps> = (
                 configSavePromiseRef.current = undefined
             }
         }
-    }, [configId, normalizedConfiguration, readOnly, validationErrors])
+    }, [configId, isAutosaveLocked, normalizedConfiguration, validationErrors])
 
     const flushPendingSave = useCallback(async (): Promise<void> => {
         if (configSavePromiseRef.current) {
@@ -1122,7 +1132,7 @@ export const AiReviewTab: FC<AiReviewTabProps> = (
     }, [flushPendingSave, onConfigSaveControllerReady])
 
     useEffect(() => {
-        if (!normalizedChallengeId || !configurationMode || !normalizedConfiguration || readOnly) {
+        if (!normalizedChallengeId || !configurationMode || !normalizedConfiguration || isAutosaveLocked) {
             return undefined
         }
 
@@ -1150,9 +1160,9 @@ export const AiReviewTab: FC<AiReviewTabProps> = (
     }, [
         configId,
         configurationMode,
+        isAutosaveLocked,
         normalizedChallengeId,
         normalizedConfiguration,
-        readOnly,
         validationErrors,
     ])
 
@@ -1182,6 +1192,10 @@ export const AiReviewTab: FC<AiReviewTabProps> = (
                 ? (
                     <div className={styles.infoBanner}>
                         AI review configuration is locked because this challenge already has submissions.
+                        {canSwitchReviewModeOnly
+                            ? ' You can still switch the review mode between AI_GATING and AI_ONLY '
+                                + 'until the review phase starts.'
+                            : undefined}
                     </div>
                 )
                 : undefined}
@@ -1295,6 +1309,17 @@ export const AiReviewTab: FC<AiReviewTabProps> = (
                                 : undefined}
                         </section>
 
+                        {canSwitchReviewModeOnly
+                            ? (
+                                <ReviewSettings
+                                    canChangeMode
+                                    configuration={configuration}
+                                    onUpdate={updateConfiguration}
+                                    readOnly
+                                />
+                            )
+                            : undefined}
+
                         <section className={styles.sectionCard}>
                             <div className={styles.sectionHeader}>
                                 <h3>Template Workflows</h3>
@@ -1332,6 +1357,7 @@ export const AiReviewTab: FC<AiReviewTabProps> = (
                         </div>
 
                         <ReviewSettings
+                            canChangeMode={canSwitchReviewModeOnly}
                             configuration={configuration}
                             onUpdate={updateConfiguration}
                             readOnly={readOnly}