Update webhook integration to use JSON instead of form-data

Removes the use of the `form-data` package and modifies the webhook payload to send data as JSON.

Replit-Commit-Author: Agent
Replit-Commit-Session-Id: cfbfe47c-0c9a-4ebf-8a41-2937407eccff
Replit-Commit-Checkpoint-Type: full_checkpoint
Replit-Commit-Screenshot-Url: https://storage.googleapis.com/screenshot-production-us-central1/1957c339-2757-4d1f-8e92-e9f71a1ce58e/cfbfe47c-0c9a-4ebf-8a41-2937407eccff/uD8abDf

package-lock.json

@@ -41,7 +41,6 @@
         "@radix-ui/react-tooltip": "^1.2.0",
         "@tanstack/react-query": "^5.60.5",
         "@types/bcrypt": "^6.0.0",
-        "@types/form-data": "^2.2.1",
         "@types/memoizee": "^0.4.12",
         "@types/node-fetch": "^2.6.13",
         "@types/pg": "^8.15.4",
@@ -59,7 +58,6 @@
         "express": "^4.21.2",
         "express-rate-limit": "^7.5.1",
         "express-session": "^1.18.1",
-        "form-data": "^4.0.4",
         "framer-motion": "^11.13.1",
         "iconv-lite": "^0.6.3",
         "input-otp": "^1.4.2",
@@ -3751,15 +3749,6 @@
         "@types/express": "*"
       }
     },
-    "node_modules/@types/form-data": {
-      "version": "2.2.1",
-      "resolved": "https://registry.npmjs.org/@types/form-data/-/form-data-2.2.1.tgz",
-      "integrity": "sha512-JAMFhOaHIciYVh8fb5/83nmuO/AHwmto+Hq7a9y8FzLDcC1KCU344XDOMEmahnrTFlHjgh4L0WJFczNIX2GxnQ==",
-      "license": "MIT",
-      "dependencies": {
-        "@types/node": "*"
-      }
-    },
     "node_modules/@types/http-errors": {
       "version": "2.0.5",
       "resolved": "https://registry.npmjs.org/@types/http-errors/-/http-errors-2.0.5.tgz",