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>

package.json

@@ -22,6 +22,7 @@
     "@dnd-kit/core": "^6.3.1",
     "@dnd-kit/sortable": "^8.0.0",
     "@dnd-kit/utilities": "^3.2.2",
+    "@hookform/resolvers": "^5.2.2",
     "@prisma/adapter-pg": "^7.8.0",
     "@prisma/client": "^7.8.0",
     "@tanstack/react-table": "^8.21.3",
@@ -39,6 +40,10 @@
     "qrcode.react": "^4.2.0",
     "react": "19.2.4",
     "react-dom": "19.2.4",
+    "react-hook-form": "^7.74.0",
+    "react-markdown": "^10.1.0",
+    "react-textarea-autosize": "^8.5.9",
+    "remark-gfm": "^4.0.1",
     "shadcn": "^4.4.0",
     "sharp": "^0.34.5",
     "sonner": "^1.7.4",
@@ -56,6 +61,7 @@
   "devDependencies": {
     "@mermaid-js/mermaid-cli": "^11.12.0",
     "@tailwindcss/postcss": "^4",
+    "@tailwindcss/typography": "^0.5.19",
     "@types/bcryptjs": "^2.4.6",
     "@types/node": "^20",
     "@types/pg": "^8.20.0",