fix(web): composer double-submit guard + onboarding session refresh + drop dotted bg

- Composer: an in-flight submit guard (ref + disabled state) so rapid double/triple clicks
  no longer fire multiple createChat calls → no duplicate threads in the sidebar.
- Onboarding: force a fresh session token (getToken skipCache) after completion so the
  middleware's metadata.onboarding_complete claim is current (belt-and-suspenders with the
  Clerk session-token 'metadata' claim added to the prod instance).
- Onboarding page: remove the paper-dot-field dotted background (bud-style clean bg).

Author: iamjr15

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

@@ -4,7 +4,7 @@ import { OnboardingFlow } from "@/components/onboarding/onboarding-flow";
 
 export default function OnboardingPage() {
   return (
-    <main className="paper-dot-field flex min-h-screen items-center justify-center bg-white px-6 py-12 text-[#1b1b1b]">
+    <main className="flex min-h-screen items-center justify-center bg-white px-6 py-12 text-[#1b1b1b]">
       <Suspense
         fallback={
           <div className="h-96 w-full max-w-[392px] rounded-[28px] border border-[#f1f1f1] bg-white" />

apps/web/src/components/home/home-composer.tsx

@@ -186,10 +186,20 @@ export function HomeComposer({
   const [value, setValue] = useState(initialPrompt ?? "");
   const [skillCreatorMode, setSkillCreatorMode] = useState(skillCreator);
   const [authRedirectTo, setAuthRedirectTo] = useState<string | null>(null);
+  // In-flight submit guard: without it, rapid double/triple clicks fire multiple createChat
+  // calls → duplicate threads in the sidebar. The ref blocks re-entry synchronously (setState
+  // is async); the state also disables the button. Only the non-navigating paths reset it —
+  // a successful submit navigates away and unmounts this component.
+  const [isSubmitting, setIsSubmitting] = useState(false);
+  const submittingRef = useRef(false);
+  const endSubmitting = useCallback(() => {
+    submittingRef.current = false;
+    setIsSubmitting(false);
+  }, []);
   const typewriterPlaceholder = useTypewriterPlaceholder();
   const intent = INTENTS.find((candidate) => candidate.id === intentId) ?? null;
   const placeholder = intent ? intent.placeholder : typewriterPlaceholder;
-  const canSubmit = value.trim().length > 0;
+  const canSubmit = value.trim().length > 0 && !isSubmitting;
   const { data: userSkills } = useQuery({
     queryFn: () => listUserSkills(getToken),
     queryKey: USER_SKILLS_QUERY,
@@ -218,9 +228,11 @@ export function HomeComposer({
 
   function submit(event?: FormEvent<HTMLFormElement>) {
     event?.preventDefault();
-    if (!canSubmit) {
+    if (!canSubmit || submittingRef.current) {
       return;
     }
+    submittingRef.current = true;
+    setIsSubmitting(true);
     const trimmed = value.trim();
     const skill = resolveSubmitSkill(repoUrl, intent, skillChip);
     const prompt = composePromptWithComposerContext({
@@ -242,12 +254,14 @@ export function HomeComposer({
         toast.error(
           "That project's latest thread is busy - wait for the run to finish or pick another project.",
         );
+        endSubmitting();
         return;
       }
       const handoff = buildExistingProjectParams(prompt).toString();
       router.push(`/chats/${encodeURIComponent(result.threadId)}?${handoff}`);
     } catch (error) {
       toast.error(error instanceof Error ? error.message : "Could not open that project.");
+      endSubmitting();
     }
   }
 
@@ -314,6 +328,7 @@ export function HomeComposer({
       // authenticated chat create.
       const params = buildLaunchParams({ model, prompt, repo: repoUrl, surface });
       setAuthRedirectTo(`/?${params.toString()}`);
+      endSubmitting();
       return;
     }
     try {
@@ -328,6 +343,7 @@ export function HomeComposer({
       router.push(`/chats/${encodeURIComponent(thread.id)}?${handoff}`);
     } catch (error) {
       toast.error(error instanceof Error ? error.message : "Could not start that chat.");
+      endSubmitting();
     }
   }
 

apps/web/src/components/onboarding/onboarding-flow.tsx

@@ -89,6 +89,10 @@ export function OnboardingFlow() {
           onboardingStep: { status: planStatus, step: "plan" },
         });
         await user?.reload();
+        // Force a fresh session token so the middleware's `metadata.onboarding_complete` claim
+        // reflects the just-set public metadata — otherwise navigating bounces back to /onboarding
+        // on the stale JWT.
+        await getToken({ skipCache: true });
       } catch {
         setPhase("retry");
         return;
@@ -99,7 +103,7 @@ export function OnboardingFlow() {
         setPhase("retry");
       }
     },
-    [mutateAsync, router, user],
+    [getToken, mutateAsync, router, user],
   );
 
   useEffect(() => {