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/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("");
+  });
 });
 
 /**