refactor: update better-auth configuration and clean up code

- Changed the version of "better-auth" to use a catalog reference in package.json and bun.lock for better dependency management.
- Removed unnecessary comments and cleaned up the code in various files to enhance readability and maintainability.
- Updated the authentication handling in hooks.server.ts to ensure proper token retrieval.
- Simplified the layout and structure of Svelte components for improved clarity and performance.

apps/web/package.json

@@ -40,7 +40,7 @@
     "@sgse-app/backend": "*",
     "@tanstack/svelte-form": "^1.19.2",
     "@types/papaparse": "^5.3.14",
-    "better-auth": "^1.3.34",
+    "better-auth": "catalog:",
     "convex": "catalog:",
     "convex-svelte": "^0.0.11",
     "date-fns": "^4.1.0",