Update CSP headers in vercel.json to allow analytics services

Add Content-Security-Policy header to allow analytics.google.com and cdn.segment.com in connect-src directive. This fixes console errors from blocked analytics requests while maintaining security restrictions.

- Allows Google Analytics (analytics.google.com)
- Allows Segment Analytics (cdn.segment.com)
- Maintains restrictive policy for other directives
- Applies to /docs/* paths

Related to EDU-631: https://linear.app/tigerdata/issue/EDU-631/update-csp-headers-in-verceljson-to-allow-analytics

Co-Authored-By: Claude Haiku 4.5 <noreply@anthropic.com>

Author: isvictorious

vercel.json

@@ -409,6 +409,19 @@
         }
       ]
     },
+    {
+      "source": "/docs/(.*)",
+      "headers": [
+        {
+          "key": "Cache-Control",
+          "value": "public, max-age=3600"
+        },
+        {
+          "key": "Content-Security-Policy",
+          "value": "default-src 'self'; script-src 'self' 'unsafe-inline' analytics.google.com; connect-src 'self' analytics.google.com cdn.segment.com; img-src 'self' data: https:; style-src 'self' 'unsafe-inline'; font-src 'self' data:; frame-ancestors 'none'; form-action 'self'"
+        }
+      ]
+    },
     {
       "source": "/(.*)",
       "headers": [