fix: clarify board grid editing affordances

apps/nextjs/src/components/board/sections/grid/test/fixed-grid-item.spec.ts

@@ -156,7 +156,7 @@ describe("fixed grid item behavior", () => {
     );
   });
 
-  test("uses the whole tile as the focusable move surface without a grab button", () => {
+  test("uses the whole tile as the focusable move surface with a visual drag affordance", () => {
     getWeatherMock().advancedOptions.title = "  Balcony forecast  ";
     renderWeather(root);
 
@@ -165,7 +165,7 @@ describe("fixed grid item behavior", () => {
     expect(entry.getAttribute("aria-label")).toBe("Balcony forecast, column 1, row 1");
     expect(entry.tabIndex).toBe(0);
     expect(entry.getAttribute("aria-describedby")).not.toBeNull();
-    expect(container.querySelector('[data-testid="board-grid-drag-handle"]')).toBeNull();
+    expect(container.querySelector('[data-testid="board-grid-drag-affordance"]')).not.toBeNull();
   });
 
   test("renders a view-only 1x1 card at the fixed 200px logical size", () => {

apps/nextjs/src/components/board/sections/grid/test/grid-drop-swap.spec.ts

@@ -7,23 +7,43 @@ const first: SectionGridPlacement = { id: "first", type: "item", x: 0, y: 0, w:
 const second: SectionGridPlacement = { id: "second", type: "item", x: 1, y: 0, w: 1, h: 1 };
 const third: SectionGridPlacement = { id: "third", type: "item", x: 2, y: 0, w: 2, h: 1 };
 const initial = [first, second, third];
+const bounds = { columnCount: 4 };
 
 describe("grid drop swapping", () => {
   test("swaps equally-sized items when one takes the other's exact slot", () => {
     const current: SectionGridPlacement[] = [{ ...first, x: 1 }, { ...second, y: 1 }, third];
 
-    expect(getDropSwapPlacements(initial, current, "first")).toEqual([{ ...first, x: 1 }, { ...second, x: 0 }, third]);
+    expect(getDropSwapPlacements(initial, current, "first", bounds)).toEqual([
+      { ...first, x: 1 },
+      { ...second, x: 0 },
+      third,
+    ]);
   });
 
-  test("keeps push behavior for different sizes or partial placement", () => {
+  test("swaps different-sized items when both destinations remain valid", () => {
+    const wide: SectionGridPlacement = { id: "wide", type: "item", x: 0, y: 0, w: 2, h: 1 };
+    const compact: SectionGridPlacement = { id: "compact", type: "item", x: 2, y: 0, w: 1, h: 1 };
+    const current = [
+      { ...wide, x: 2 },
+      { ...compact, y: 1 },
+    ];
+
+    expect(getDropSwapPlacements([wide, compact], current, "wide", bounds)).toEqual([
+      { ...wide, x: 2 },
+      { ...compact, x: 0 },
+    ]);
+  });
+
+  test("keeps push behavior when a swap would overlap another item or exceed the section", () => {
     const differentSize: SectionGridPlacement[] = [{ ...first, x: 2 }, second, { ...third, y: 1 }];
     const partialPlacement: SectionGridPlacement[] = [{ ...third, x: 1 }, first, { ...second, y: 1 }];
 
-    expect(getDropSwapPlacements(initial, differentSize, "first")).toBeNull();
-    expect(getDropSwapPlacements(initial, partialPlacement, "third")).toBeNull();
+    expect(getDropSwapPlacements(initial, differentSize, "first", bounds)).toBeNull();
+    expect(getDropSwapPlacements(initial, partialPlacement, "third", bounds)).toBeNull();
+    expect(getDropSwapPlacements(initial, [{ ...third, x: 1 }, first, second], "third", { columnCount: 2 })).toBeNull();
   });
 
   test("does nothing when the item did not move", () => {
-    expect(getDropSwapPlacements(initial, initial, "first")).toBeNull();
+    expect(getDropSwapPlacements(initial, initial, "first", bounds)).toBeNull();
   });
 });