M14: TaskDialog (create/edit) + story auto-promotion (#21)

* chore(ST-1112): add deps for task dialog

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): add shared zod schema for task dialog

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): add missing MD3 tokens for task dialog

outline-variant, on-error-container, status-review (light + dark)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): add saveTask and deleteTask server actions for TaskDialog

Unified create/edit action (saveTask) replaces separate formData-based
actions for the new TaskDialog. Uses shared zod schema, structured
SaveTaskResult union type, and context-aware revalidatePath for both
sprint and backlog routes.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): add TaskDialog component (create & edit mode)

Builds the full TaskDialog on top of the existing @base-ui/react
Dialog primitive. Covers create mode, edit mode (status field +
created_at metadata + delete), dirty-check AlertDialog, delete
confirm AlertDialog, Cmd+Enter submit, and per-field char counters.
Uses react-hook-form + zodResolver against the shared taskSchema.
Priority and status are extracted to PrioritySegmented and
StatusSelect sub-components using MD3 tokens throughout.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): refactor task-list to open TaskDialog via URL params

Replaces inline create/edit forms with router.push navigation:
- Clicking a task row → ?editTask=<id>
- "+ Taak" button → ?newTask=1&storyId=<storyId>
Removes CreateTaskForm, EditSubmitButton, updateTaskAction, and
createTaskAction from the component. Status toggle and DnD remain
unchanged. Rows now have cursor-pointer and keyboard a11y.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): wire TaskDialog into sprint page via searchParams

Sprint page now reads ?newTask, ?storyId, and ?editTask query params.
For edit mode: fetches the task server-side with productAccessFilter
scope (invalid/foreign IDs redirect to closePath). Renders TaskDialog
when either param is present. closePath is the sprint route without
query params.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): add Suspense skeleton for edit-mode task loading

Extracts task fetch into EditTaskLoader (async server component) so
the sprint board renders immediately while the task loads.
TaskDialogSkeleton shows 3 grey bars during the fetch. Invalid or
out-of-scope task IDs redirect to closePath.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): render description as markdown in task-detail-dialog

Solo task detail now renders description via react-markdown +
remark-gfm with prose styling. Sanitizes script/iframe elements.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* test(ST-1112): add saveTask/deleteTask server action tests

Covers all three demo-policy layers and cross-tenant scope:
demo blocked (403), unauthenticated blocked, validation 422,
edit cross-tenant forbidden, create cross-tenant forbidden,
and happy-path for both edit and create.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): add updateTaskStatusWithStoryPromotion helper

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1112): wire story-promotion into saveTask and PATCH /api/tasks/:id

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* docs(ST-1112): add task-dialog doc and architecture note

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* chore: extend allowed tools in settings.local.json

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1113): add 200ms animation-delay to TaskDialogSkeleton to prevent flicker

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1114): add DirtyCloseGuard reusable component for dirty-form close confirmation

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* feat(ST-1114): add shared Markdown wrapper, apply to task-detail and story-dialog

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

* chore: allow grep -E pattern in settings.local.json

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

---------

Co-authored-by: Claude Sonnet 4.6 <noreply@anthropic.com>

app/(app)/products/[id]/sprint/page.tsx

@@ -1,3 +1,4 @@
+import { Suspense } from 'react'
 import { notFound, redirect } from 'next/navigation'
 import { getSession } from '@/lib/auth'
 import { getAccessibleProduct } from '@/lib/product-access'
@@ -6,14 +7,24 @@ import { SprintBoardClient } from '@/components/sprint/sprint-board-client'
 import { SprintHeader } from '@/components/sprint/sprint-header'
 import type { SprintStory, PbiWithStories, ProductMember } from '@/components/sprint/sprint-backlog'
 import type { Task } from '@/components/sprint/task-list'
+import { TaskDialog } from '@/app/_components/tasks/task-dialog'
+import { EditTaskLoader } from '@/app/_components/tasks/edit-task-loader'
+import { TaskDialogSkeleton } from '@/app/_components/tasks/task-dialog-skeleton'
 import Link from 'next/link'
 
 interface Props {
   params: Promise<{ id: string }>
+  searchParams: Promise<{
+    newTask?: string
+    storyId?: string
+    editTask?: string
+  }>
 }
 
-export default async function SprintBoardPage({ params }: Props) {
+export default async function SprintBoardPage({ params, searchParams }: Props) {
   const { id } = await params
+  const { newTask, storyId: storyIdParam, editTask } = await searchParams
+
   const session = await getSession()
   if (!session.userId) redirect('/login')
 
@@ -104,6 +115,7 @@ export default async function SprintBoardPage({ params }: Props) {
 
   const sprintStoryIdList = sprintStories.map(s => s.id)
   const isDemo = session.isDemo ?? false
+  const closePath = `/products/${id}/sprint`
 
   return (
     <div className="flex flex-col h-full">
@@ -134,6 +146,27 @@ export default async function SprintBoardPage({ params }: Props) {
           ← Product Backlog
         </Link>
       </div>
+
+      {newTask && (
+        <TaskDialog
+          storyId={storyIdParam}
+          productId={id}
+          closePath={closePath}
+          isDemo={isDemo}
+        />
+      )}
+
+      {editTask && !newTask && (
+        <Suspense fallback={<TaskDialogSkeleton />}>
+          <EditTaskLoader
+            taskId={editTask}
+            userId={session.userId}
+            productId={id}
+            closePath={closePath}
+            isDemo={isDemo}
+          />
+        </Suspense>
+      )}
     </div>
   )
 }