feat(FN-779): make inline editor taller with 4-row default and mount-time resize

- Increase inline editor textarea default rows from 1 to 4 for better multi-line editing
- Add mount-time auto-resize to fit content on initial render
- Add regression tests for taller inline editor behavior
- Update documentation to reflect the new taller editor defaults

packages/dashboard/README.md

@@ -40,7 +40,7 @@ AI-guided interactive planning for creating well-specified tasks from high-level
 
 ### Task Management
 - **Kanban Board**: Drag-and-drop task management across columns (Triage, Todo, In Progress, In Review, Done)
-- **Inline Editing**: Quick-edit a task's description directly on the board for Triage and Todo columns. Double-click a card or use the pencil icon — visible on hover for desktop, always visible on mobile for touch accessibility. Inline editing changes only the description; the title is preserved. To edit both title and description, use the task detail modal.
+- **Inline Editing**: Quick-edit a task's description directly on the board for Triage and Todo columns. The editor opens as a taller multi-line editing area (4 visible lines) for comfortable editing of longer descriptions, and auto-grows to fit existing content. Double-click a card or use the pencil icon — visible on hover for desktop, always visible on mobile for touch accessibility. Inline editing changes only the description; the title is preserved. To edit both title and description, use the task detail modal.
 - **Task Detail Editing**: Edit task title and description directly in the task detail modal. Click the pencil icon in the modal header (available for Triage and Todo tasks) to enter edit mode.
 - **List View**: Alternative tabular view for tasks with sorting and filtering. The "Hide Done" toggle hides both Done and Archived tasks for an active-work-only view.
 - **Model Selection at Creation**: Choose executor and validator AI models while creating tasks from the board or list view, or leave them unset to use the global defaults. Quick-add model dropdowns in both the board triage column and the list view honor saved favorite providers and pinned models, matching the rest of the dashboard model UI.

packages/dashboard/app/components/TaskCard.tsx

@@ -161,10 +161,16 @@ function TaskCardComponent({
     setEditDescription(task.description || "");
   }, [task.id, task.description]);
 
-  // Auto-focus on description textarea when entering edit mode
+  // Auto-focus and auto-resize description textarea when entering edit mode
   useEffect(() => {
-    if (isEditing) {
-      descTextareaRef.current?.focus();
+    if (isEditing && descTextareaRef.current) {
+      const el = descTextareaRef.current;
+      el.focus();
+      // Apply the same resize logic used in handleDescChange so the textarea
+      // opens at the correct height for existing long descriptions without
+      // requiring the user to type first.
+      el.style.height = "auto";
+      el.style.height = el.scrollHeight + "px";
     }
   }, [isEditing]);
 
@@ -511,7 +517,7 @@ function TaskCardComponent({
             onKeyDown={handleDescKeyDown}
             onBlur={handleBlur}
             disabled={isSaving}
-            rows={1}
+            rows={4}
           />
           {isSaving && (
             <div className="card-edit-loading">

packages/dashboard/app/components/__tests__/TaskCard.test.tsx

@@ -1387,6 +1387,53 @@ describe("TaskCard inline editing", () => {
     expect(screen.queryByPlaceholderText(/Task title/i)).toBeNull();
     expect(screen.getByPlaceholderText(/Task description/i)).toBeDefined();
   });
+
+  it("opens the description textarea with 4 visible rows", () => {
+    const task = makeEditableTask({ description: "Some text" });
+
+    render(
+      <TaskCard
+        task={task}
+        onOpenDetail={vi.fn()}
+        addToast={noopToast}
+        onUpdateTask={noopUpdateTask}
+      />
+    );
+
+    // Enter edit mode
+    const card = document.querySelector('[data-id="FN-099"]');
+    fireEvent.doubleClick(card!);
+
+    const descTextarea = screen.getByPlaceholderText(/Task description/i) as HTMLTextAreaElement;
+    expect(descTextarea).toBeDefined();
+    expect(descTextarea.getAttribute("rows")).toBe("4");
+  });
+
+  it("applies mount-time auto-resize for existing long descriptions", () => {
+    // A multi-line description that would exceed the default 4-row height
+    const longDescription = Array(10).fill("This is a line of description text.").join("\n");
+    const task = makeEditableTask({ description: longDescription });
+
+    render(
+      <TaskCard
+        task={task}
+        onOpenDetail={vi.fn()}
+        addToast={noopToast}
+        onUpdateTask={noopUpdateTask}
+      />
+    );
+
+    // Enter edit mode
+    const card = document.querySelector('[data-id="FN-099"]');
+    fireEvent.doubleClick(card!);
+
+    const descTextarea = screen.getByPlaceholderText(/Task description/i) as HTMLTextAreaElement;
+    // The mount-time resize effect sets height to scrollHeight + "px".
+    // In JSDOM, scrollHeight is 0 (no real layout), so the style ends up
+    // as "0px" — but the important thing is the effect *did* set the
+    // height property, proving the auto-resize logic runs on mount.
+    expect(descTextarea.style.height).not.toBe("");
+  });
 });
 
 /**

packages/dashboard/app/styles.css

@@ -3974,7 +3974,7 @@ body {
   resize: none;
   overflow: hidden;
   line-height: 1.4;
-  min-height: 38px;
+  min-height: 80px;
   transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
 }