[feat] dreamverse: steering-only UI — drop auto-rollout mode selector

Remove the pre-session Auto rollout / Steering segmented control and make
manual continuation (steering) the sole mode: default it on in the session
store and keep it on across project/lobby resets. Leaves a short steering
hint in its place.

apps/dreamverse/web/src/app/page.tsx

@@ -1773,7 +1773,7 @@ export default function Page() {
 			sessionNotice: preserveSessionNotice ? sessionStore.get().sessionNotice : "",
 			sessionExpired: preserveSessionNotice ? sessionStore.get().sessionExpired : false,
 			projectResetPending: false,
-			manualContinuationMode: false,
+			manualContinuationMode: true,
 			waitingForSegmentPrompt: false,
 		});
 		rewriteStore.resetSessionState();
@@ -1800,7 +1800,7 @@ export default function Page() {
 			sessionNotice: "",
 			sessionExpired: false,
 			projectResetPending: false,
-			manualContinuationMode: false,
+			manualContinuationMode: true,
 			waitingForSegmentPrompt: false,
 		});
 		rewriteStore.resetSessionState();

apps/dreamverse/web/src/components/ChatBar.tsx

@@ -382,38 +382,8 @@ export default function ChatBar({
 
 			{!sessionStarted && (
 				<div className="flex flex-col items-center gap-1.5">
-					<div className="inline-flex rounded-full border border-input bg-card/65 p-0.5 shadow-sm backdrop-blur-sm">
-						<button
-							type="button"
-							onClick={() => onModeChange(false)}
-							aria-pressed={!manualContinuationEnabled}
-							className={cn(
-								"rounded-full px-4 py-1 text-xs font-medium transition-colors",
-								!manualContinuationEnabled
-									? "bg-primary text-primary-foreground shadow-sm"
-									: "text-muted-foreground hover:text-foreground",
-							)}
-						>
-							Auto rollout
-						</button>
-						<button
-							type="button"
-							onClick={() => onModeChange(true)}
-							aria-pressed={manualContinuationEnabled}
-							className={cn(
-								"rounded-full px-4 py-1 text-xs font-medium transition-colors",
-								manualContinuationEnabled
-									? "bg-primary text-primary-foreground shadow-sm"
-									: "text-muted-foreground hover:text-foreground",
-							)}
-						>
-							Steering
-						</button>
-					</div>
 					<p className="text-[11px] text-muted-foreground">
-						{manualContinuationEnabled
-							? "Drive each scene yourself — type what happens next, one segment at a time."
-							: "Automatic 6-segment story rollout."}
+						Drive each scene yourself — type what happens next, one segment at a time.
 					</p>
 				</div>
 			)}

apps/dreamverse/web/src/stores/session.ts

@@ -51,7 +51,9 @@ const DEFAULT_SESSION_STATE: SessionState = {
   livePromptRewriteMode: false,
   sessionExpired: false,
   projectResetPending: false,
-  manualContinuationMode: false,
+  // Steering-only product: every session drives scenes manually. There is no
+  // auto-rollout mode and no UI selector, so this stays true throughout.
+  manualContinuationMode: true,
   waitingForSegmentPrompt: false,
 };