diff --git a/desktop/src-tauri/capabilities/default.json b/desktop/src-tauri/capabilities/default.json
index 9f082cc4ef..97ee30cbdd 100644
--- a/desktop/src-tauri/capabilities/default.json
+++ b/desktop/src-tauri/capabilities/default.json
@@ -10,6 +10,7 @@
     "core:window:allow-set-badge-label",
     "core:window:allow-request-user-attention",
     "core:window:allow-set-focus",
+    "core:window:allow-set-title",
     "core:window:allow-start-dragging",
     "core:window:allow-toggle-maximize",
     "core:window:allow-unminimize",
diff --git a/desktop/src/app/AppShell.tsx b/desktop/src/app/AppShell.tsx
index db1d24879a..58f8748582 100644
--- a/desktop/src/app/AppShell.tsx
+++ b/desktop/src/app/AppShell.tsx
@@ -932,6 +932,7 @@ export function AppShell() {
                           hasCommunityRail={hasCommunityRail}
                           isHuddleRoom={isHuddleRoom}
                           isHuddleRoomStarting={isHuddleRoomStarting}
+                          unframed={isCompanionWindow}
                           mainInsetRef={mainInsetRef}
                           terminal={
                             <TerminalBootstrap {...effectiveTerminalContext} />
diff --git a/desktop/src/app/AppShellChannelSurface.tsx b/desktop/src/app/AppShellChannelSurface.tsx
index da6907a902..7fdd7f7254 100644
--- a/desktop/src/app/AppShellChannelSurface.tsx
+++ b/desktop/src/app/AppShellChannelSurface.tsx
@@ -11,6 +11,7 @@ type AppShellChannelSurfaceProps = {
   hasCommunityRail: boolean;
   isHuddleRoom: boolean;
   isHuddleRoomStarting: boolean;
+  unframed?: boolean;
   mainInsetRef: React.RefObject<HTMLElement | null>;
   terminal?: React.ReactNode;
 };
@@ -20,12 +21,13 @@ export function AppShellChannelSurface({
   hasCommunityRail,
   isHuddleRoom,
   isHuddleRoomStarting,
+  unframed = false,
   mainInsetRef,
   terminal,
 }: AppShellChannelSurfaceProps) {
   const { isMobile, openMobile, state: sidebarState } = useSidebar();
   const hasCollapsedSidebarGutter =
-    !isHuddleRoom &&
+    !unframed &&
     !hasCommunityRail &&
     (isMobile ? !openMobile : sidebarState === "collapsed");
 
@@ -35,11 +37,11 @@ export function AppShellChannelSurface({
         ref={mainInsetRef}
         className={cn(
           "isolate z-0 min-h-0 min-w-0 overflow-hidden",
-          isHuddleRoom ? "bg-background" : "bg-sidebar",
+          unframed ? "bg-background" : "bg-sidebar",
           hasCollapsedSidebarGutter && "pl-2",
         )}
-        data-buzz-content-surface={isHuddleRoom ? true : undefined}
-        data-buzz-content-unframed={isHuddleRoom ? true : undefined}
+        data-buzz-content-surface={unframed ? true : undefined}
+        data-buzz-content-unframed={unframed ? true : undefined}
         data-buzz-glass-inset
         data-buzz-shadow-viewport
         style={chromeCssVarDefaults as React.CSSProperties}
@@ -51,7 +53,7 @@ export function AppShellChannelSurface({
           />
         ) : null}
         {isHuddleRoom && !isHuddleRoomStarting ? <HuddleRoomHeader /> : null}
-        <BuzzTheme.ContentSurface terminal={terminal} unframed={isHuddleRoom}>
+        <BuzzTheme.ContentSurface terminal={terminal} unframed={unframed}>
           {isHuddleRoomStarting ? <HuddleStartingView /> : children}
         </BuzzTheme.ContentSurface>
       </SidebarInset>
diff --git a/desktop/src/app/BuzzThemeSurfaces.tsx b/desktop/src/app/BuzzThemeSurfaces.tsx
index b7912c98bc..45101d5e65 100644
--- a/desktop/src/app/BuzzThemeSurfaces.tsx
+++ b/desktop/src/app/BuzzThemeSurfaces.tsx
@@ -27,7 +27,7 @@ export function ContentSurface({
 }: {
   children: ReactNode;
   terminal?: ReactNode;
-  /** Used by dedicated huddle windows, which should not resemble app cards. */
+  /** Used by dedicated companion windows, which should not resemble app cards. */
   unframed?: boolean;
 }) {
   return (
diff --git a/desktop/src/features/agents/lib/agentActivityWindow.test.mjs b/desktop/src/features/agents/lib/agentActivityWindow.test.mjs
new file mode 100644
index 0000000000..a40fd4d578
--- /dev/null
+++ b/desktop/src/features/agents/lib/agentActivityWindow.test.mjs
@@ -0,0 +1,20 @@
+import assert from "node:assert/strict";
+import { describe, it } from "node:test";
+
+import { agentActivityWindowTitle } from "./agentActivityWindow.ts";
+
+describe("agentActivityWindowTitle", () => {
+  it("names both the agent and channel", () => {
+    assert.equal(
+      agentActivityWindowTitle("Mongo", "buzz-inline-chip-wrap"),
+      "Mongo · #buzz-inline-chip-wrap",
+    );
+  });
+
+  it("does not duplicate a supplied channel hash", () => {
+    assert.equal(
+      agentActivityWindowTitle(" Mongo ", " #design "),
+      "Mongo · #design",
+    );
+  });
+});
diff --git a/desktop/src/features/agents/lib/agentActivityWindow.ts b/desktop/src/features/agents/lib/agentActivityWindow.ts
index a4520828de..ffcf2ac324 100644
--- a/desktop/src/features/agents/lib/agentActivityWindow.ts
+++ b/desktop/src/features/agents/lib/agentActivityWindow.ts
@@ -15,3 +15,26 @@ export function isAgentActivityWindow(): boolean {
     return false;
   }
 }
+
+/** Build the concise native title for a channel-scoped activity window. */
+export function agentActivityWindowTitle(
+  agentName: string,
+  channelName: string,
+): string {
+  const normalizedAgentName = agentName.trim() || "Agent";
+  const normalizedChannelName = channelName.trim().replace(/^#+/, "");
+  return `${normalizedAgentName} · #${normalizedChannelName}`;
+}
+
+/** Keep a companion window's native title aligned with its resolved scope. */
+export async function setAgentActivityWindowTitle(
+  agentName: string,
+  channelName: string,
+): Promise<boolean> {
+  if (!isAgentActivityWindow() || !channelName.trim()) return false;
+
+  await getCurrentWindow().setTitle(
+    agentActivityWindowTitle(agentName, channelName),
+  );
+  return true;
+}
diff --git a/desktop/src/features/channels/ui/AgentSessionThreadPanel.tsx b/desktop/src/features/channels/ui/AgentSessionThreadPanel.tsx
index c1933f14bb..a0d5c9402d 100644
--- a/desktop/src/features/channels/ui/AgentSessionThreadPanel.tsx
+++ b/desktop/src/features/channels/ui/AgentSessionThreadPanel.tsx
@@ -9,6 +9,10 @@ import {
 import { toast } from "sonner";
 
 import { useAgentWorking } from "@/features/agents/agentWorkingSignal";
+import {
+  isAgentActivityWindow,
+  setAgentActivityWindowTitle,
+} from "@/features/agents/lib/agentActivityWindow";
 import { isManagedAgentActive } from "@/features/agents/lib/managedAgentControlActions";
 import {
   mergeObserverEventWindows,
@@ -96,6 +100,7 @@ export function AgentSessionThreadPanel({
   widthPx,
   transparentChrome = false,
 }: AgentSessionThreadPanelProps) {
+  const isDedicatedActivityWindow = isAgentActivityWindow();
   const isLive = isManagedAgentActive(agent);
   const isOverlay = useIsThreadPanelOverlay();
   const sessionChannelId = channelId ?? channel?.id ?? null;
@@ -106,7 +111,10 @@ export function AgentSessionThreadPanel({
     sessionChannelId,
   );
   const canStopCurrentTurn = isWorking && canInterruptTurn;
-  useEscapeKey(onClose, isOverlay || isSinglePanelView);
+  useEscapeKey(
+    onClose,
+    (isOverlay || isSinglePanelView) && !isDedicatedActivityWindow,
+  );
 
   const scrollRef = React.useRef<HTMLDivElement>(null);
   const contentRef = React.useRef<HTMLDivElement>(null);
@@ -236,6 +244,15 @@ export function AgentSessionThreadPanel({
     profiles,
     preferResolvedSelfLabel: true,
   });
+  React.useEffect(() => {
+    if (!scopeChannelName) return;
+
+    void setAgentActivityWindowTitle(agentLabel, scopeChannelName).catch(
+      (error) => {
+        console.error("Failed to update agent activity window title:", error);
+      },
+    );
+  }, [agentLabel, scopeChannelName]);
   const viewLabel = showRawFeed ? "Raw ACP activity" : "Activity";
   const headerScopeLabel = `${viewLabel} · ${scopeLabel}`;
   const animateActivity = useTranscriptAnimationEnabled();
@@ -469,6 +486,7 @@ export function AgentSessionThreadPanel({
           backdrop={layout !== "split" && !isOverlay}
           backdropSurface="soft"
           inset={layout !== "split" ? "wide" : "default"}
+          showCloseAction={!isDedicatedActivityWindow}
         >
           {agentHeaderContent}
         </AuxiliaryPanelHeader>
diff --git a/desktop/src/features/channels/ui/ChannelScreen.tsx b/desktop/src/features/channels/ui/ChannelScreen.tsx
index 2e0501d3b0..8c38e237ad 100644
--- a/desktop/src/features/channels/ui/ChannelScreen.tsx
+++ b/desktop/src/features/channels/ui/ChannelScreen.tsx
@@ -98,6 +98,7 @@ export function ChannelScreen({
   targetMessageEvents,
   targetMessageId,
 }: ChannelScreenProps) {
+  const isDedicatedActivityWindow = isAgentActivityWindow();
   const { goHome } = useAppNavigation();
   const { activeCommunity } = useCommunities();
   const {
@@ -713,10 +714,13 @@ export function ChannelScreen({
   const isNarrowPanelViewport =
     channelContentWidthPx > 0 &&
     channelContentWidthPx < AUXILIARY_PANEL_SINGLE_COLUMN_BREAKPOINT_PX;
+  // A dedicated activity window is the panel itself, not a responsive channel
+  // view. Keep the channel timeline out of that window at every width.
   const isSinglePanelView =
-    isNarrowPanelViewport &&
-    activeChannel?.channelType !== "forum" &&
-    hasAuxiliaryPanel;
+    isDedicatedActivityWindow ||
+    (isNarrowPanelViewport &&
+      activeChannel?.channelType !== "forum" &&
+      hasAuxiliaryPanel);
   const shouldCompactHeaderActions =
     hasAuxiliaryPanel &&
     channelContentWidthPx > 0 &&
@@ -853,6 +857,7 @@ export function ChannelScreen({
               <React.Suspense
                 fallback={
                   <ChannelScreenLoadingFallback
+                    includeHeader={!isDedicatedActivityWindow}
                     isHuddleTranscript={isHuddleTranscript}
                   />
                 }
diff --git a/desktop/src/features/channels/ui/ChannelScreenLoadingFallback.tsx b/desktop/src/features/channels/ui/ChannelScreenLoadingFallback.tsx
index a566b71d90..461fb2d19a 100644
--- a/desktop/src/features/channels/ui/ChannelScreenLoadingFallback.tsx
+++ b/desktop/src/features/channels/ui/ChannelScreenLoadingFallback.tsx
@@ -2,13 +2,15 @@ import { HuddleStartingView } from "@/features/huddle/components/HuddleStartingV
 import { ViewLoadingFallback } from "@/shared/ui/ViewLoadingFallback";
 
 export function ChannelScreenLoadingFallback({
+  includeHeader = true,
   isHuddleTranscript,
 }: {
+  includeHeader?: boolean;
   isHuddleTranscript: boolean;
 }) {
   return isHuddleTranscript ? (
     <HuddleStartingView />
   ) : (
-    <ViewLoadingFallback includeHeader kind="channel" />
+    <ViewLoadingFallback includeHeader={includeHeader} kind="channel" />
   );
 }
diff --git a/desktop/src/shared/layout/AuxiliaryPanelHeader.tsx b/desktop/src/shared/layout/AuxiliaryPanelHeader.tsx
index 5140c4d8d5..547e7f81e0 100644
--- a/desktop/src/shared/layout/AuxiliaryPanelHeader.tsx
+++ b/desktop/src/shared/layout/AuxiliaryPanelHeader.tsx
@@ -19,6 +19,7 @@ type AuxiliaryPanelHeaderProps = Omit<
   inset?: "default" | "wide";
   mode?: AuxiliaryPanelMode;
   resizeBorder?: boolean;
+  showCloseAction?: boolean;
   surface?: AuxiliaryPanelSurface;
   /** Render header content without its own backdrop for a shared parent chrome. */
   transparent?: boolean;
@@ -113,6 +114,7 @@ export function AuxiliaryPanelHeader({
   inset = "default",
   mode,
   resizeBorder = false,
+  showCloseAction = true,
   surface = "default",
   transparent,
   ...props
@@ -159,7 +161,7 @@ export function AuxiliaryPanelHeader({
           data-tauri-drag-region
           {...props}
         >
-          {renderAuxiliaryPanelHeaderContent(children)}
+          {renderAuxiliaryPanelHeaderContent(children, showCloseAction)}
         </div>
       </>
     );
@@ -181,15 +183,21 @@ export function AuxiliaryPanelHeader({
         data-tauri-drag-region
       >
         <div className="flex h-9 min-w-0 items-center gap-2.5">
-          {renderAuxiliaryPanelHeaderContent(children)}
+          {renderAuxiliaryPanelHeaderContent(children, showCloseAction)}
         </div>
       </div>
     </div>
   );
 }
 
-function renderAuxiliaryPanelHeaderContent(children: React.ReactNode) {
-  const { foundActions, content } = attachCloseActionToHeaderActions(children);
+function renderAuxiliaryPanelHeaderContent(
+  children: React.ReactNode,
+  showCloseAction: boolean,
+) {
+  const { foundActions, content } = attachCloseActionToHeaderActions(
+    children,
+    showCloseAction,
+  );
 
   if (foundActions) {
     return content;
@@ -198,12 +206,15 @@ function renderAuxiliaryPanelHeaderContent(children: React.ReactNode) {
   return (
     <>
       {children}
-      <AuxiliaryPanelHeaderActions includeCloseAction />
+      <AuxiliaryPanelHeaderActions includeCloseAction={showCloseAction} />
     </>
   );
 }
 
-function attachCloseActionToHeaderActions(children: React.ReactNode): {
+function attachCloseActionToHeaderActions(
+  children: React.ReactNode,
+  includeCloseAction: boolean,
+): {
   content: React.ReactNode;
   foundActions: boolean;
 } {
@@ -216,11 +227,14 @@ function attachCloseActionToHeaderActions(children: React.ReactNode): {
 
     if (child.type === AuxiliaryPanelHeaderActions) {
       foundActions = true;
-      return React.cloneElement(child, { includeCloseAction: true });
+      return React.cloneElement(child, { includeCloseAction });
     }
 
     if (child.type === React.Fragment) {
-      const nested = attachCloseActionToHeaderActions(child.props.children);
+      const nested = attachCloseActionToHeaderActions(
+        child.props.children,
+        includeCloseAction,
+      );
 
       if (!nested.foundActions) {
         return child;
diff --git a/desktop/src/shared/layout/auxiliaryPanelContext.test.mjs b/desktop/src/shared/layout/auxiliaryPanelContext.test.mjs
index 69cea29974..7a06e9d661 100644
--- a/desktop/src/shared/layout/auxiliaryPanelContext.test.mjs
+++ b/desktop/src/shared/layout/auxiliaryPanelContext.test.mjs
@@ -8,6 +8,7 @@ import { AuxiliaryPanel } from "./AuxiliaryPanel/index.ts";
 import { AuxiliaryPanelBody } from "./AuxiliaryPanel/index.ts";
 import {
   AuxiliaryPanelHeader,
+  AuxiliaryPanelHeaderActions,
   AuxiliaryPanelHeaderGroup,
 } from "./AuxiliaryPanel/index.ts";
 import {
@@ -177,6 +178,33 @@ test("AuxiliaryPanelHeader renders a generic close action from context", () => {
   assert.match(html, /data-testid="auxiliary-panel-close"/);
 });
 
+test("AuxiliaryPanelHeader can suppress its close action", () => {
+  const html = render(
+    React.createElement(
+      AuxiliaryPanel,
+      {
+        header: React.createElement(
+          AuxiliaryPanelHeader,
+          { showCloseAction: false },
+          React.createElement(AuxiliaryPanelHeaderGroup, null, "Title"),
+          React.createElement(
+            AuxiliaryPanelHeaderActions,
+            null,
+            React.createElement("button", { type: "button" }, "Settings"),
+          ),
+        ),
+        onClose: () => {},
+        widthPx: 420,
+      },
+      "Panel",
+    ),
+  );
+
+  assert.match(html, />Settings</);
+  assert.doesNotMatch(html, /aria-label="Close panel"/);
+  assert.doesNotMatch(html, /data-testid="auxiliary-panel-close"/);
+});
+
 test("AuxiliaryPanelHeader keeps resize border in single-panel mode when requested", () => {
   const html = render(
     React.createElement(