fix: mobile session header duplication, composer overflow, stuck mock state

server/scripts/mock-rpc-host.ts

@@ -142,7 +142,12 @@ function streamCannedTurn() {
 	];
 	let index = 0;
 	const tick = () => {
-		if (index >= steps.length) return;
+		if (index >= steps.length) {
+			// Turn finished: drop the timer so get_state reports isStreaming
+			// false again — the UI keys its queue/stop mode off that flag.
+			streamTimer = undefined;
+			return;
+		}
 		steps[index]!();
 		index++;
 		streamTimer = setTimeout(tick, 250);
@@ -253,7 +258,9 @@ function handleFrame(frame: unknown) {
 			pendingPrompt = { id, command: type };
 			write({ id, type: "response", command: type, success: true });
 			write({ type: "turn_start" });
-			// Echo the prompt back as a user message, images included.
+			// Echo the prompt back as a user message, images included. Real omp
+			// finalizes the entry with message_end; without it the UI keeps the
+			// message in streaming state forever ("agent is working…" never clears).
 			const images = Array.isArray(obj.images) ? (obj.images as unknown[]) : [];
 			const content =
 				images.length > 0
@@ -262,10 +269,9 @@ function handleFrame(frame: unknown) {
 							...images.map(image => ({ type: "image", ...(image as Record<string, unknown>) })),
 						]
 					: String(obj.message ?? "");
-			write({
-				type: "message_start",
-				message: { role: "user", content, timestamp: Date.now() },
-			});
+			const echo = { role: "user", content, timestamp: Date.now() };
+			write({ type: "message_start", message: echo });
+			write({ type: "message_end", message: echo });
 			streamCannedTurn();
 			return;
 		}

web/src/components/chat/Composer.tsx

@@ -506,11 +506,14 @@ export function Composer({ store, snapshot, assistant = false }: ComposerProps)
 							</div>
 						)}
 
-						<div className="ml-auto flex shrink-0 items-center gap-2">
+						{/* min-w-0 (not shrink-0): the model chip is the elastic item —
+							    it truncates so the row still fits narrow screens instead of
+							    pushing the primary button out of the composer. */}
+						<div className="ml-auto flex min-w-0 items-center gap-2">
 							{/* Queued message count */}
 							{queuedCount > 0 ? (
 								<span
-									className="flex h-7 items-center gap-1 rounded-md border border-border bg-surface-2 px-2 font-mono text-[10px] text-fg-2"
+									className="flex h-7 shrink-0 items-center gap-1 rounded-md border border-border bg-surface-2 px-2 font-mono text-[10px] text-fg-2"
 									title={`${queuedCount} message(s) queued`}
 								>
 									<ListPlus className="h-3 w-3" />
@@ -527,10 +530,10 @@ export function Composer({ store, snapshot, assistant = false }: ComposerProps)
 											type="button"
 											onClick={() => toggleMenu("model")}
 											title="Switch model"
-											className="flex h-7 items-center gap-1.5 rounded-md border border-border bg-surface-2 px-2.5 font-mono text-[10.5px] text-fg-1 hover:border-border-strong"
+											className="flex h-7 min-w-0 items-center gap-1.5 rounded-md border border-border bg-surface-2 px-2.5 font-mono text-[10.5px] text-fg-1 hover:border-border-strong"
 										>
 											<Sparkles className="h-3 w-3 shrink-0 text-cat-meta" />
-											<span className="max-w-[7.5rem] truncate sm:max-w-44">
+											<span className="min-w-0 max-w-[7.5rem] truncate sm:max-w-44">
 												{modelLabel ??
 													(currentModel ? `${currentModel.provider}/${currentModel.id}` : "model")}
 											</span>
@@ -562,7 +565,7 @@ export function Composer({ store, snapshot, assistant = false }: ComposerProps)
 									</div>
 
 									{/* Thinking level */}
-									<div className="relative">
+									<div className="relative shrink-0">
 										<button
 											type="button"
 											onClick={() => toggleMenu("think")}

web/src/pages/SessionDetailPage.tsx

@@ -135,9 +135,13 @@ export function SessionDetailPage() {
 				) : null}
 
 				<div className="ml-auto flex items-center gap-2">
-					<ThemeToggle />
-					<SettingsLink />
-					<LogoutButton />
+					{/* The mobile top bar already carries these three — a second copy
+						    here would show them twice on narrow screens. */}
+					<div className="hidden items-center gap-2 lg:flex">
+						<ThemeToggle />
+						<SettingsLink />
+						<LogoutButton />
+					</div>
 					<button
 						type="button"
 						onClick={() => setShowSide(s => !s)}