[backport cloud/1.41] feat: add SHA-256 hashed email to GTM dataLayer for sign_up/login events (#10637)

Backport of #10591 to `cloud/1.41`

Conflict resolution: adapted the two new email-hashing tests to use the
cloud/1.41 test style (direct `new GtmTelemetryProvider()` with inline
config) since the helper functions (`createInitializedProvider`,
`lastDataLayerEntry`) from #9770 were never backported to this branch.

All 6 tests pass locally.

┆Issue is synchronized with this [Notion
page](https://www.notion.so/PR-10637-backport-cloud-1-41-feat-add-SHA-256-hashed-email-to-GTM-dataLayer-for-sign_up-login--3316d73d365081638938f3a5653d972e)
by [Unito](https://www.unito.io)

src/platform/telemetry/providers/cloud/GtmTelemetryProvider.test.ts

@@ -80,4 +80,50 @@ describe('GtmTelemetryProvider', () => {
       event: 'subscription_success'
     })
   })
+
+  it('pushes normalized email as user_data before auth event', () => {
+    window.__CONFIG__ = {
+      gtm_container_id: 'GTM-TEST123'
+    }
+
+    const provider = new GtmTelemetryProvider()
+
+    provider.trackAuth({
+      method: 'email',
+      is_new_user: true,
+      user_id: 'uid-123',
+      email: '  Test@Example.com  '
+    })
+
+    const dl = window.dataLayer as Record<string, unknown>[]
+    const userData = dl.find((entry) => 'user_data' in entry)
+    expect(userData).toMatchObject({
+      user_data: { email: 'test@example.com' }
+    })
+
+    // Verify user_data is pushed before the sign_up event
+    const userDataIndex = dl.findIndex((entry) => 'user_data' in entry)
+    const signUpIndex = dl.findIndex(
+      (entry) => (entry as Record<string, unknown>).event === 'sign_up'
+    )
+    expect(userDataIndex).toBeLessThan(signUpIndex)
+  })
+
+  it('does not push user_data when email is absent', () => {
+    window.__CONFIG__ = {
+      gtm_container_id: 'GTM-TEST123'
+    }
+
+    const provider = new GtmTelemetryProvider()
+
+    provider.trackAuth({
+      method: 'google',
+      is_new_user: false,
+      user_id: 'uid-456'
+    })
+
+    const dl = window.dataLayer as Record<string, unknown>[]
+    const userData = dl.find((entry) => 'user_data' in entry)
+    expect(userData).toBeUndefined()
+  })
 })

src/platform/telemetry/providers/cloud/GtmTelemetryProvider.ts

@@ -103,6 +103,12 @@ export class GtmTelemetryProvider implements TelemetryProvider {
       ...(metadata.user_id ? { user_id: metadata.user_id } : {})
     }
 
+    if (metadata.email) {
+      window.dataLayer?.push({
+        user_data: { email: metadata.email.trim().toLowerCase() }
+      })
+    }
+
     if (metadata.is_new_user) {
       this.pushEvent('sign_up', basePayload)
       return

src/platform/telemetry/types.ts

@@ -24,6 +24,7 @@ export interface AuthMetadata {
   method?: 'email' | 'google' | 'github'
   is_new_user?: boolean
   user_id?: string
+  email?: string
   referrer_url?: string
   utm_source?: string
   utm_medium?: string

src/stores/firebaseAuthStore.ts

@@ -350,7 +350,8 @@ export const useFirebaseAuthStore = defineStore('firebaseAuth', () => {
       useTelemetry()?.trackAuth({
         method: 'email',
         is_new_user: false,
-        user_id: result.user.uid
+        user_id: result.user.uid,
+        email: result.user.email ?? undefined
       })
     }
 
@@ -371,7 +372,8 @@ export const useFirebaseAuthStore = defineStore('firebaseAuth', () => {
       useTelemetry()?.trackAuth({
         method: 'email',
         is_new_user: true,
-        user_id: result.user.uid
+        user_id: result.user.uid,
+        email: result.user.email ?? undefined
       })
     }
 
@@ -392,7 +394,8 @@ export const useFirebaseAuthStore = defineStore('firebaseAuth', () => {
         method: 'google',
         is_new_user:
           options?.isNewUser || additionalUserInfo?.isNewUser || false,
-        user_id: result.user.uid
+        user_id: result.user.uid,
+        email: result.user.email ?? undefined
       })
     }
 
@@ -413,7 +416,8 @@ export const useFirebaseAuthStore = defineStore('firebaseAuth', () => {
         method: 'github',
         is_new_user:
           options?.isNewUser || additionalUserInfo?.isNewUser || false,
-        user_id: result.user.uid
+        user_id: result.user.uid,
+        email: result.user.email ?? undefined
       })
     }