FN-7873: fix mobile floating-window header drag being intersected by page pan-y lockdown

Restores reliable single-finger dragging of movable FloatingWindow headers on mobile by reasserting touch-action: none at the mobile breakpoint, and adds regression coverage for the touch drag path.

- Reassert touch-action: none on movable FloatingWindow headers within the mobile media query, excluding full-screen sheet variants (chat, task-detail, workflow-editor, automation, mission-interview, file-browser, pr-create, artifacts-gallery), so the drag-handle contract isn't overridden by the global pan-y lockdown on mobile.
- Add a test verifying the movable mobile drag-handle selector keeps touch-action: none alongside the other opted-out draggable selectors (right-dock-expand-modal header, terminal header).
- Add a test exercising the captured pointermove drag path (pointerdown/move/up with pointer capture) confirming the window repositions correctly on touch input.
- Add a patch changeset for @runfusion/fusion documenting the fix.

Files changed:
 .changeset/fn-7873-mobile-modal-header-drag.md                       |  7 +++
 packages/dashboard/app/components/FloatingWindow.css                 |  8 +++
 packages/dashboard/app/components/__tests__/FloatingWindow.test.tsx  | 59 ++++++++++++++++++++++
 3 files changed, 74 insertions(+)

Fusion-Task-Id: FN-7873
Fusion-Task-Lineage: 96f2b199-549e-4cab-a42b-05946a7bae86
Co-authored-by: Fusion (runfusion.ai) <noreply@runfusion.ai>

.changeset/fn-7873-mobile-modal-header-drag.md

@@ -0,0 +1,7 @@
+---
+"@runfusion/fusion": patch
+---
+
+summary: Restore reliable mobile header dragging for movable floating modals.
+category: fix
+dev: Reasserts the FloatingWindow mobile touch-action contract and covers touch pointer dragging.

packages/dashboard/app/components/FloatingWindow.css

@@ -99,6 +99,14 @@ 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.
 */
 @media (max-width: 768px) {
+  /*
+  FNXC:FloatingWindow 2026-07-12-17:35:
+  Mobile keeps the global `styles.css` pan-y lockdown so the dashboard cannot drift, but movable FloatingWindow headers must still resolve to an effective `touch-action: none`. Reassert the drag-handle contract at the mobile breakpoint, excluding full-screen sheet variants, so a single-finger header drag stays on the captured pointermove stream instead of being intersected back into page pan by the ancestor chain. Desktop drag/resize and mobile sheet variants are unchanged.
+  */
+  .floating-window:not(.floating-window--chat):not(.floating-window--task-detail):not(.floating-window--workflow-editor):not(.floating-window--automation):not(.floating-window--mission-interview):not(.floating-window--file-browser):not(.floating-window--pr-create):not(.artifacts-gallery-window) .floating-window__header {
+    touch-action: none;
+  }
+
   .floating-window--chat {
     inset: 0 !important;
     width: 100vw !important;

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

@@ -1,9 +1,18 @@
 import { render, screen, fireEvent } from "@testing-library/react";
 import { readFileSync } from "node:fs";
 import { beforeEach, describe, expect, it, vi } from "vitest";
+import { loadAllAppCss } from "../../test/cssFixture";
 import { FloatingWindow } from "../FloatingWindow";
 
 const floatingWindowCss = readFileSync("app/components/FloatingWindow.css", "utf8");
+const allAppCss = loadAllAppCss();
+
+function cssRuleFor(css: string, selector: string): string {
+  const start = css.indexOf(`${selector} {`);
+  if (start === -1) return "";
+  const end = css.indexOf("}", start);
+  return css.slice(start, end);
+}
 
 /*
 FNXC:FloatingWindow 2026-06-22-20:45:
@@ -56,6 +65,56 @@ describe("FloatingWindow", () => {
     expect(floatingWindowCss).not.toContain("var(--shadow-xl)");
   });
 
+  it("keeps movable mobile drag handles opted out of the pan-y touch lockdown", () => {
+    expect(allAppCss).toContain("html,");
+    expect(allAppCss).toContain("body {");
+    expect(allAppCss).toContain("touch-action: pan-y;");
+    expect(allAppCss).toContain("* {");
+    expect(allAppCss).toContain("#root {");
+
+    const movableFloatingWindowSelector = ".floating-window:not(.floating-window--chat):not(.floating-window--task-detail):not(.floating-window--workflow-editor):not(.floating-window--automation):not(.floating-window--mission-interview):not(.floating-window--file-browser):not(.floating-window--pr-create):not(.artifacts-gallery-window) .floating-window__header";
+    expect(cssRuleFor(floatingWindowCss, movableFloatingWindowSelector)).toContain("touch-action: none;");
+
+    for (const selector of [
+      ".right-dock-expand-modal__header--draggable",
+      ".terminal-header--draggable",
+    ]) {
+      expect(cssRuleFor(allAppCss, selector)).toContain("touch-action: none;");
+    }
+  });
+
+  it("moves a visible-header window through the captured touch drag path", () => {
+    render(
+      <FloatingWindow
+        windowKey="touch-drag"
+        title="A very long movable floating window title that still starts drag from the ellipsized title text"
+        onClose={() => {}}
+        defaultSize={{ width: 320, height: 240 }}
+        defaultPosition={{ x: 80, y: 90 }}
+        minSize={{ width: 240, height: 180 }}
+      >
+        <div>touch drag body</div>
+      </FloatingWindow>
+    );
+
+    const panel = screen.getByTestId("floating-window-touch-drag");
+    const header = screen.getByTestId("floating-window-drag-handle-touch-drag");
+    const titleText = screen.getByText(/very long movable floating window title/i);
+    const setPointerCapture = vi.fn();
+    const releasePointerCapture = vi.fn();
+    Object.defineProperty(header, "setPointerCapture", { configurable: true, value: setPointerCapture });
+    Object.defineProperty(header, "releasePointerCapture", { configurable: true, value: releasePointerCapture });
+
+    fireEvent.pointerDown(titleText, { pointerId: 17, pointerType: "touch", clientX: 100, clientY: 120 });
+    fireEvent.pointerMove(header, { pointerId: 17, pointerType: "touch", clientX: 140, clientY: 150 });
+    fireEvent.pointerUp(header, { pointerId: 17, pointerType: "touch", clientX: 140, clientY: 150 });
+
+    expect(setPointerCapture).toHaveBeenCalledWith(17);
+    expect(releasePointerCapture).toHaveBeenCalledWith(17);
+    expect(panel.style.left).toBe("120px");
+    expect(panel.style.top).toBe("120px");
+  });
+
   it("can hide generic chrome and delegate dragging to a child header", () => {
     render(
       <FloatingWindow