fix(webapp): fullscreen chat column fills takeover height

Author: kathiekiwi

apps/webapp/app/components/dashboard-agent/panel-layout.dom.test.ts

@@ -220,15 +220,17 @@ describe("FloatingAgentWindow keeps its child mounted across every mode transiti
 });
 
 describe("FloatingAgentWindow's fullscreen geometry", () => {
-  it("pins the exact takeover classes from before the mode switcher (8dea45a09)", () => {
+  it("pins the exact takeover classes, including the flex column that fills the takeover's height", () => {
     container = document.createElement("div");
     document.body.appendChild(container);
     root = createRoot(container);
     act(() => {
       root!.render(createElement(FloatingAgentWindow, { mode: "fullscreen" }, () => null));
     });
     const outer = container.firstElementChild as HTMLDivElement;
-    expect(outer.className).toBe("absolute inset-0 z-10 bg-background-bright");
+    expect(outer.className).toBe("absolute inset-0 z-10 flex flex-col bg-background-bright");
+    expect(outer.classList.contains("flex")).toBe(true);
+    expect(outer.classList.contains("flex-col")).toBe(true);
     expect(outer.getAttribute("style")).toBeNull();
   });
 });

apps/webapp/app/components/dashboard-agent/panel-layout.tsx

@@ -69,7 +69,7 @@ export function writeAgentMode(mode: DashboardAgentMode): void {
 }
 
 function agentTakeoverClassName(fullscreen: boolean): string {
-  return fullscreen ? "absolute inset-0 z-10 bg-background-bright" : "h-full";
+  return fullscreen ? "absolute inset-0 z-10 flex flex-col bg-background-bright" : "h-full";
 }
 
 // `invisible` rather than `display: none`: only this preserves the computed layout, so