feat: 🎸 posthog (#1929)

added in src

# Description

Please include a summary of the changes and the related issue. Please
also include relevant motivation and context.

## Checklist before requesting a review

Please delete options that are not relevant.

- [ ] My code follows the style guidelines of this project
- [ ] I have performed a self-review of my code
- [ ] I have commented hard-to-understand areas
- [ ] I have ideally added tests that prove my fix is effective or that
my feature works
- [ ] New and existing unit tests pass locally with my changes
- [ ] Any dependent changes have been merged

## Screenshots (if appropriate):

frontend/next.config.js

@@ -36,6 +36,7 @@ const ContentSecurityPolicy = {
     "https://fonts.googleapis.com",
     process.env.NEXT_PUBLIC_SUPABASE_URL,
     "https://api.june.so",
+    "https://us.posthog.com",
     process.env.NEXT_PUBLIC_FRONTEND_URL,
   ],
   "connect-src": [
@@ -69,8 +70,11 @@ const ContentSecurityPolicy = {
     process.env.NEXT_PUBLIC_FRONTEND_URL,
     "https://www.google-analytics.com/",
     "https://js.stripe.com",
+    "https://us.posthog.com"
+  ],
+  "frame-src": ["https://js.stripe.com",
+    "https://us.posthog.com"
   ],
-  "frame-src": ["https://js.stripe.com"],
   "frame-ancestors": ["'none'"],
   "style-src": ["'unsafe-inline'", process.env.NEXT_PUBLIC_FRONTEND_URL],
 };