feat: add PostHog tracking for enterprise lead form submission

- Add trackEnterpriseLeadFormSubmitted function to use-tracking.ts
- Track form data on submit: requestType (saas/self-hosted), name, company, email, message
- Add inline styles to onboarding-layout.tsx to prevent FOUC
- Add 4 new tests for tracking behavior (25 total tests)

PostHog event: 'enterprise_lead_form_submitted'
Properties: request_type, name, company, email, message, plus common properties

Co-authored-by: openhands <openhands@all-hands.dev>

frontend/__tests__/components/features/onboarding/information-request-form.test.tsx

@@ -14,6 +14,14 @@ vi.mock("react-router", async () => {
   };
 });
 
+// Mock useTracking
+const mockTrackEnterpriseLeadFormSubmitted = vi.fn();
+vi.mock("#/hooks/use-tracking", () => ({
+  useTracking: () => ({
+    trackEnterpriseLeadFormSubmitted: mockTrackEnterpriseLeadFormSubmitted,
+  }),
+}));
+
 describe("InformationRequestForm", () => {
   const defaultProps = {
     requestType: "saas" as RequestType,
@@ -190,6 +198,16 @@ describe("InformationRequestForm", () => {
       expect(mockNavigate).not.toHaveBeenCalled();
     });
 
+    it("should not call tracking when form is submitted with empty fields", async () => {
+      const user = userEvent.setup();
+      renderWithRouter();
+
+      const submitButton = screen.getByRole("button", { name: "ENTERPRISE$FORM_SUBMIT" });
+      await user.click(submitButton);
+
+      expect(mockTrackEnterpriseLeadFormSubmitted).not.toHaveBeenCalled();
+    });
+
     it("should navigate to homepage with modal state when form is submitted with all fields filled", async () => {
       const user = userEvent.setup();
       renderWithRouter();
@@ -207,6 +225,70 @@ describe("InformationRequestForm", () => {
       });
     });
 
+    it("should call tracking with form data when form is submitted successfully", async () => {
+      const user = userEvent.setup();
+      renderWithRouter({ ...defaultProps, requestType: "saas" });
+
+      await user.type(screen.getByTestId("form-input-name"), "John Doe");
+      await user.type(screen.getByTestId("form-input-company"), "Acme Inc");
+      await user.type(screen.getByTestId("form-input-email"), "john@example.com");
+      await user.type(screen.getByTestId("form-input-message"), "Hello world");
+
+      const submitButton = screen.getByRole("button", { name: "ENTERPRISE$FORM_SUBMIT" });
+      await user.click(submitButton);
+
+      expect(mockTrackEnterpriseLeadFormSubmitted).toHaveBeenCalledTimes(1);
+      expect(mockTrackEnterpriseLeadFormSubmitted).toHaveBeenCalledWith({
+        requestType: "saas",
+        name: "John Doe",
+        company: "Acme Inc",
+        email: "john@example.com",
+        message: "Hello world",
+      });
+    });
+
+    it("should call tracking with self-hosted request type", async () => {
+      const user = userEvent.setup();
+      renderWithRouter({ ...defaultProps, requestType: "self-hosted" });
+
+      await user.type(screen.getByTestId("form-input-name"), "Jane Smith");
+      await user.type(screen.getByTestId("form-input-company"), "Tech Corp");
+      await user.type(screen.getByTestId("form-input-email"), "jane@techcorp.com");
+      await user.type(screen.getByTestId("form-input-message"), "Interested in self-hosted");
+
+      const submitButton = screen.getByRole("button", { name: "ENTERPRISE$FORM_SUBMIT" });
+      await user.click(submitButton);
+
+      expect(mockTrackEnterpriseLeadFormSubmitted).toHaveBeenCalledWith({
+        requestType: "self-hosted",
+        name: "Jane Smith",
+        company: "Tech Corp",
+        email: "jane@techcorp.com",
+        message: "Interested in self-hosted",
+      });
+    });
+
+    it("should trim whitespace from form fields before tracking", async () => {
+      const user = userEvent.setup();
+      renderWithRouter();
+
+      await user.type(screen.getByTestId("form-input-name"), "  John Doe  ");
+      await user.type(screen.getByTestId("form-input-company"), "  Acme Inc  ");
+      await user.type(screen.getByTestId("form-input-email"), "  john@example.com  ");
+      await user.type(screen.getByTestId("form-input-message"), "  Hello world  ");
+
+      const submitButton = screen.getByRole("button", { name: "ENTERPRISE$FORM_SUBMIT" });
+      await user.click(submitButton);
+
+      expect(mockTrackEnterpriseLeadFormSubmitted).toHaveBeenCalledWith({
+        requestType: "saas",
+        name: "John Doe",
+        company: "Acme Inc",
+        email: "john@example.com",
+        message: "Hello world",
+      });
+    });
+
     it("should have valid aria-invalid state when field has value", async () => {
       const user = userEvent.setup();
       renderWithRouter();

frontend/src/components/features/onboarding/information-request-form.tsx

@@ -2,6 +2,7 @@ import { useState } from "react";
 import { useTranslation } from "react-i18next";
 import { useNavigate } from "react-router";
 import { I18nKey } from "#/i18n/declaration";
+import { useTracking } from "#/hooks/use-tracking";
 import { Card } from "#/ui/card";
 import { Text } from "#/ui/typography";
 import { FormInput } from "./form-input";
@@ -22,6 +23,7 @@ export function InformationRequestForm({
 }: InformationRequestFormProps) {
   const { t } = useTranslation();
   const navigate = useNavigate();
+  const { trackEnterpriseLeadFormSubmitted } = useTracking();
   const [formData, setFormData] = useState({
     name: "",
     company: "",
@@ -46,6 +48,15 @@ export function InformationRequestForm({
     }
 
     // TODO: Implement actual form submission API call
+    // Track form submission in PostHog
+    trackEnterpriseLeadFormSubmitted({
+      requestType,
+      name: formData.name.trim(),
+      company: formData.company.trim(),
+      email: formData.email.trim(),
+      message: formData.message.trim(),
+    });
+
     // Navigate to homepage with state to show confirmation modal
     navigate("/", { state: { showRequestSubmittedModal: true } });
   };

frontend/src/hooks/use-tracking.ts

@@ -129,6 +129,29 @@ export const useTracking = () => {
     });
   };
 
+  const trackEnterpriseLeadFormSubmitted = ({
+    requestType,
+    name,
+    company,
+    email,
+    message,
+  }: {
+    requestType: "saas" | "self-hosted";
+    name: string;
+    company: string;
+    email: string;
+    message: string;
+  }) => {
+    posthog.capture("enterprise_lead_form_submitted", {
+      request_type: requestType,
+      name,
+      company,
+      email,
+      message,
+      ...commonProperties,
+    });
+  };
+
   return {
     trackLoginButtonClick,
     trackConversationCreated,
@@ -142,5 +165,6 @@ export const useTracking = () => {
     trackAddTeamMembersButtonClick,
     trackOnboardingCompleted,
     trackSaasSelfhostedInquiry,
+    trackEnterpriseLeadFormSubmitted,
   };
 };