Add PostHog.

frontend/package-lock.json

@@ -40,6 +40,7 @@
         "monaco-themes": "^0.4.4",
         "next": "14.1.3",
         "next-themes": "^0.3.0",
+        "posthog-js": "^1.147.0",
         "react": "^18.3.1",
         "react-dom": "^18",
         "react-hook-form": "^7.51.3",
@@ -3269,6 +3270,30 @@
       "resolved": "https://registry.npmjs.org/postcss-value-parser/-/postcss-value-parser-4.2.0.tgz",
       "integrity": "sha512-1NNCs6uurfkVbeXG4S8JFT9t19m45ICnif8zWLd5oPSZ50QnwMfK+H3jv408d4jw/7Bttv5axS5IiHoLaVNHeQ=="
     },
+    "node_modules/posthog-js": {
+      "version": "1.147.0",
+      "resolved": "https://registry.npmjs.org/posthog-js/-/posthog-js-1.147.0.tgz",
+      "integrity": "sha512-cALKIcix1W9xMsfUUI/QUFhtBeabDGsQCb3lpZEFd7WCPNLOcGmpeomm4xMX7MO2OnfK6Ov91/HNyfK1wncjSA==",
+      "dependencies": {
+        "fflate": "^0.4.8",
+        "preact": "^10.19.3",
+        "web-vitals": "^4.0.1"
+      }
+    },
+    "node_modules/posthog-js/node_modules/fflate": {
+      "version": "0.4.8",
+      "resolved": "https://registry.npmjs.org/fflate/-/fflate-0.4.8.tgz",
+      "integrity": "sha512-FJqqoDBR00Mdj9ppamLa/Y7vxm+PRmNWA67N846RvsoYVMKB4q3y/de5PA7gUmRMYK/8CMz2GDZQmCRN1wBcWA=="
+    },
+    "node_modules/preact": {
+      "version": "10.22.1",
+      "resolved": "https://registry.npmjs.org/preact/-/preact-10.22.1.tgz",
+      "integrity": "sha512-jRYbDDgMpIb5LHq3hkI0bbl+l/TQ9UnkdQ0ww+lp+4MMOdqaUYdFc5qeyP+IV8FAd/2Em7drVPeKdQxsiWCf/A==",
+      "funding": {
+        "type": "opencollective",
+        "url": "https://opencollective.com/preact"
+      }
+    },
     "node_modules/pvtsutils": {
       "version": "1.3.5",
       "resolved": "https://registry.npmjs.org/pvtsutils/-/pvtsutils-1.3.5.tgz",
@@ -4083,6 +4108,11 @@
         "@types/jasmine": "^3.6.3"
       }
     },
+    "node_modules/web-vitals": {
+      "version": "4.2.1",
+      "resolved": "https://registry.npmjs.org/web-vitals/-/web-vitals-4.2.1.tgz",
+      "integrity": "sha512-U6bAxeudnhDqcXNl50JC4hLlqox9DZnngxfISZm3DMZnonW35xtJOVUc091L+DOY+6hVZVpKXoiCP0RiT6339Q=="
+    },
     "node_modules/webcrypto-core": {
       "version": "1.7.9",
       "resolved": "https://registry.npmjs.org/webcrypto-core/-/webcrypto-core-1.7.9.tgz",