feat(ui): restructure lead forms, self-serve Buy Credits, dialog blur

Revised lead-capture surfaces and credits bar:

- Dialog overlay gains backdrop blur (bg-black/60 backdrop-blur-sm).
- Shared primitives: LeadModalShell (icon/eyebrow header, scrollable body,
  sticky footer, trust-line slot), PhoneField (react-international-phone,
  dark, E.164 out), FormTrustLine ("Average response: under 10 minutes...").
- HireExpertModal: Name, Company, Job title, agent goal, Phone (required),
  monthly volume. EnterpriseModal: + work email (required logged-out),
  conditional deployment (yes/no/maybe, source-gated), agent goal.
  OnboardingModal: drop useCase. Phone mandatory except onboarding.
- Volume buckets match the backend qualifier (0-5k/5k-100k/100k+/not-sure).
- Delete TopUpModal; DograhCreditsCard now self-serve Buy Credits (amount
  chips $5/$10/$25/$50/$100 + custom min $5 → startTopUp seam) + Hire an
  Expert + dashed custom-pricing link opening Enterprise (billing_custom_pricing).
- PostHog events: drop topup_*, add buy_credits_clicked,
  buy_credits_amount_selected, custom_pricing_clicked. LeadFormsContext
  drops topup; LeadKind/LeadSource updated.
- Introduce a single --cta warm accent token (CTAs + focus rings only).

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

ui/src/components/lead-forms/onboardingServiceClient.ts

@@ -0,0 +1,47 @@
+// Thin client for the SEPARATE user_onboarding service (its own base URL).
+// Not part of the generated Dograh SDK — a different host. Sends the SAME Dograh
+// Bearer token the browser already holds. All calls are BEST-EFFORT: failures are
+// swallowed so a down/erroring service never blocks the user from the product.
+
+// Base URL of the user_onboarding service; unset → calls are skipped (no-op).
+const BASE_URL = process.env.NEXT_PUBLIC_ONBOARDING_API_URL;
+
+// POST a JSON body to the onboarding service with the Dograh auth token attached.
+async function post(path: string, token: string, body: unknown): Promise<void> {
+  if (!BASE_URL) return; // service not configured — skip silently
+  try {
+    await fetch(`${BASE_URL}${path}`, {
+      method: "POST",
+      headers: {
+        "Content-Type": "application/json",
+        Authorization: `Bearer ${token}`,
+      },
+      body: JSON.stringify(body),
+    });
+  } catch {
+    // Best-effort: PostHog already captured the event; never block the user.
+  }
+}
+
+// Map a lead kind to its endpoint path on the onboarding service.
+const LEAD_PATH: Record<"hire_expert" | "enterprise", string> = {
+  hire_expert: "/api/v1/leads/hire-expert",
+  enterprise: "/api/v1/leads/enterprise",
+};
+
+// Persist a lead submission (hire-expert / enterprise).
+export async function postLeadToService(
+  kind: "hire_expert" | "enterprise",
+  token: string,
+  body: Record<string, unknown>,
+): Promise<void> {
+  await post(LEAD_PATH[kind], token, body);
+}
+
+// Persist an onboarding submission (or skip — body carries `skipped`).
+export async function postOnboardingToService(
+  token: string,
+  body: Record<string, unknown>,
+): Promise<void> {
+  await post("/api/v1/onboarding", token, body);
+}