FN-8766: align task detail popup inset

Align the desktop Task Detail popup header and content edges without losing resize access.

- Remove the Task Detail desktop body gutter while preserving shared scrollbar clearance.
- Move Task Detail east resize targets outside the painted shell and retain mobile clipping.
- Add geometry regression coverage and a patch changeset.

Files changed:
 .changeset/fn-8766-task-detail-popup-spacing.md    |  7 +++
 .../dashboard/app/components/FloatingWindow.css    | 30 +++++++++++
 .../components/__tests__/FloatingWindow.test.tsx   | 32 +++++++-----
 ...etailModal.responsive-and-dependencies.test.tsx | 58 ++++++++++++++++++++++
 4 files changed, 115 insertions(+), 12 deletions(-)

Fusion-Task-Id: FN-8766

Fusion-Task-Lineage: b4d23a5e-51d0-45cb-8cbb-4fefb81fa09f

Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

.changeset/fn-8766-task-detail-popup-spacing.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Align the floating Task Detail popup close control with its header edge.
+category: fix
+dev: Moves only Task Detail desktop resize targets outboard while retaining shared scrollbar clearance.

packages/dashboard/app/components/FloatingWindow.css

@@ -261,6 +261,35 @@ Phone sheets are strictly below 768px. At exactly 768px this query must not matc
 FNXC:ChatModal 2026-06-22-14:49:
 On mobile/narrow app viewports, opening Quick Chat should present the full Chat modal as a full-screen sheet instead of a small draggable desktop window. Scope this to the chat FloatingWindow and override the inline desktop geometry only at the mobile breakpoint; desktop pop-out behavior remains movable/resizable.
 */
+/*
+FNXC:TaskDetailLayout 2026-08-03-19:36:
+FN-8766 keeps the desktop Task Detail popup's visible header/content edge symmetric while
+preserving the shared body's scrollbar clearance for every other FloatingWindow consumer. This
+headerless host owns its close button, so remove only its visible body gutter and move its desktop
+east resize hit areas outside the painted shell; the scrollbar remains fully usable and the close
+control does not sit behind a resize target. Tablet retains its existing touch geometry and phones
+remain full-screen sheets below.
+*/
+.floating-window--task-detail:not(.floating-window--tablet-viewport) {
+  overflow: visible;
+}
+
+.floating-window--task-detail:not(.floating-window--tablet-viewport) .floating-window__body {
+  margin-inline-end: 0;
+}
+
+.floating-window--task-detail:not(.floating-window--tablet-viewport) .floating-window__resize-handle--e {
+  right: calc(var(--space-sm) * -1);
+}
+
+.floating-window--task-detail:not(.floating-window--tablet-viewport) .floating-window__resize-handle--ne {
+  right: calc(var(--space-lg) * -1);
+}
+
+.floating-window--task-detail:not(.floating-window--tablet-viewport) .floating-window__resize-handle--se {
+  right: calc(var(--space-lg) * -1);
+}
+
 /*
 FNXC:ModalTouchGeometry 2026-07-26-13:25:
 FN-8606 migrated core and workflow dialogs share FloatingWindow's pointer contract. Their
@@ -452,6 +481,7 @@ all floating affordances so persisted desktop geometry cannot imply a draggable
   */
   .floating-window--task-detail {
     inset: 0 !important;
+    overflow: hidden !important;
     width: 100vw !important;
     height: 100dvh !important;
     min-width: 0 !important;

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

@@ -161,12 +161,14 @@ describe("FloatingWindow", () => {
     expect(cssRuleContaining(floatingWindowCss, ".floating-window__resize-handle--ne", "right: 0;")).toContain("right: 0;");
     expect(cssRuleContaining(floatingWindowCss, ".floating-window__resize-handle--se", "right: 0;")).toContain("right: 0;");
 
-    // No shared caller may move a right handle back into the reserved scrollbar
-    // gutter, nor override the body gutter, AT DESKTOP WIDTHS. Mobile full-screen
-    // sheet overrides (inside @media) are legitimate and excluded from this scan.
+    /*
+    FNXC:TaskDetailLayout 2026-08-03-19:36:
+    FN-8766 is the sole desktop exception: its header-owned close control requires a symmetric
+    painted edge, so its gutter is removed only while its east resize targets move outboard.
+    Every unrelated consumer keeps the shared scrollbar-clearance geometry.
+    */
     const desktopAppCss = stripAtMediaBlocks(allAppCss);
     for (const callerClass of [
-      "floating-window--task-detail",
       "floating-window--automation",
       "floating-window--mission-interview",
       "floating-window--pr-create",
@@ -182,14 +184,20 @@ describe("FloatingWindow", () => {
       expect(bodyRules.some((rule) => /margin-inline-end\s*:/.test(rule)), callerClass).toBe(false);
     }
 
+    const desktopTaskBody = cssRuleContaining(
+      desktopAppCss,
+      ".floating-window--task-detail:not(.floating-window--tablet-viewport) .floating-window__body",
+      "margin-inline-end",
+    );
+    expect(desktopTaskBody).toContain("margin-inline-end: 0;");
+    expect(cssRuleContaining(desktopAppCss, ".floating-window--task-detail:not(.floating-window--tablet-viewport) .floating-window__resize-handle--e", "right")).toContain("right: calc(var(--space-sm) * -1);");
+    expect(cssRuleContaining(desktopAppCss, ".floating-window--task-detail:not(.floating-window--tablet-viewport) .floating-window__resize-handle--ne", "right")).toContain("right: calc(var(--space-lg) * -1);");
+    expect(cssRuleContaining(desktopAppCss, ".floating-window--task-detail:not(.floating-window--tablet-viewport) .floating-window__resize-handle--se", "right")).toContain("right: calc(var(--space-lg) * -1);");
+
     /*
-    FNXC:MobileTaskPopups 2026-07-17-08:20:
-    Regression guard for the mobile task-detail left-shift fix: the full-screen
-    task-detail sheet hides all resize handles, so FN-8015's inherited
-    `margin-inline-end: var(--space-lg)` body gutter only added dead space on the
-    right and shifted the whole panel left. The mobile breakpoint must zero it so
-    `.detail-body`'s own padding defines both insets equally. This is the sole
-    legitimate body-gutter override and lives only inside the mobile @media block.
+    FNXC:MobileTaskPopups 2026-08-03-19:36:
+    The full-screen task-detail sheet hides every resize handle, so the inherited gutter must
+    remain zero and the desktop outboard-target host must resume clipping for sheet geometry.
     */
     const mobileTaskDetailBody = cssRuleContaining(
       allAppCss,
@@ -197,7 +205,7 @@ describe("FloatingWindow", () => {
       "margin-inline-end",
     );
     expect(mobileTaskDetailBody).toContain("margin-inline-end: 0;");
-    expect(cssRulesForClass(desktopAppCss, "floating-window--task-detail").some((rule) => rule.includes("floating-window__body"))).toBe(false);
+    expect(cssRuleContaining(allAppCss, ".floating-window--task-detail", "overflow: hidden !important;")).toContain("overflow: hidden !important;");
 
     /*
     FNXC:ModalTouchGeometry 2026-08-01-03:48:

packages/dashboard/app/components/__tests__/TaskDetailModal.responsive-and-dependencies.test.tsx

@@ -24,6 +24,7 @@ import {
   setupTaskDetailModalHooks,
 } from "./TaskDetailModal.test-helpers";
 import { TaskDetailModal, TaskDetailContent } from "../TaskDetailModal";
+import { FloatingWindow } from "../FloatingWindow";
 import {
   assertModalGeometryRecoveryAndSheetContracts,
   assertRenderedModalTouchGeometry,
@@ -856,6 +857,63 @@ describe("TaskDetailModal", () => {
       }
     });
 
+    it("keeps the floating task header symmetric without sacrificing its resize targets", () => {
+      const floatingCss = readFileSync(resolve(__dirname, "../FloatingWindow.css"), "utf8");
+      const desktopTaskSelector = ".floating-window--task-detail:not(.floating-window--tablet-viewport)";
+      const taskPopupBody = getExactCssRuleBlock(floatingCss, `${desktopTaskSelector} .floating-window__body`);
+      const sharedBody = getExactCssRuleBlock(floatingCss, ".floating-window__body");
+      const header = getExactCssRuleBlock(readDashboardStylesSource(), ".modal-header");
+      const eastResize = getExactCssRuleBlock(floatingCss, `${desktopTaskSelector} .floating-window__resize-handle--e`);
+      const northEastResize = getExactCssRuleBlock(floatingCss, `${desktopTaskSelector} .floating-window__resize-handle--ne`);
+      const southEastResize = getExactCssRuleBlock(floatingCss, `${desktopTaskSelector} .floating-window__resize-handle--se`);
+      const onRequestClose = vi.fn();
+
+      /*
+      FNXC:TaskDetailLayout 2026-08-03-19:36:
+      The shared body reserves desktop scrollbar clearance. Task Detail moves only its resize
+      hit areas outboard, so the embedded header retains matching tokenized edges.
+      */
+      expect(sharedBody).toContain("margin-inline-end: var(--space-lg);");
+      expect(taskPopupBody).toContain("margin-inline-end: 0;");
+      expect(header).toContain("padding: var(--modal-padding);");
+      expect(eastResize).toContain("right: calc(var(--space-sm) * -1);");
+      expect(northEastResize).toContain("right: calc(var(--space-lg) * -1);");
+      expect(southEastResize).toContain("right: calc(var(--space-lg) * -1);");
+
+      const { baseElement, unmount } = render(
+        <FloatingWindow
+          windowKey="task-detail-inset"
+          title="FN-8766"
+          onClose={onRequestClose}
+          hideHeader
+          dragHandleSelector=".task-detail-content--embedded > .modal-header"
+          className="floating-window--task-detail"
+          layer="task-detail"
+        >
+          <TaskDetailContent
+            task={makeTask({ id: "FN-8766", title: "A task title long enough to exercise header alignment" })}
+            onMoveTask={noopMove}
+            onDeleteTask={noopDelete}
+            onMergeTask={noopMerge}
+            onOpenDetail={noopOpenDetail}
+            addToast={noop}
+            embedded
+            onRequestClose={onRequestClose}
+          />
+        </FloatingWindow>,
+      );
+
+      const popup = baseElement.querySelector("[data-testid='floating-window-task-detail-inset']");
+      const close = screen.getByRole("button", { name: "Close" });
+      expect(popup).toHaveClass("floating-window--task-detail");
+      expect(popup?.querySelector(".task-detail-content--embedded > .modal-header")).toContainElement(close);
+      expect(close).toHaveClass("task-detail-floating-close");
+      expect(popup?.querySelectorAll(".floating-window__resize-handle")).toHaveLength(8);
+      fireEvent.click(close);
+      expect(onRequestClose).toHaveBeenCalledTimes(1);
+      unmount();
+    });
+
     it("uses production FloatingWindow geometry for touch drag, eight-direction resize, recovery, and sheets", () => {
       const mount = () => render(
         <TaskDetailModal