Upgrade dependencies to latest stable versions, migrate Tailwind CSS v3 to v4

Bumped React, Supabase JS, and type packages to latest patch/minor releases.
Migrated the Tailwind pipeline from the v3 JS-config format to v4's CSS-first
@theme setup (@tailwindcss/postcss, @import "tailwindcss" in globals.css),
removing tailwind.config.ts and autoprefixer since v4 handles both natively.
All existing color/radius/font tokens were ported 1:1 so no component classes
needed to change. TypeScript and ESLint were bumped and tested against their
true latest majors (7.x and 10.x) but both broke the build/lint pipeline, so
they're pinned to the latest working minor instead (TypeScript 5.9.3, ESLint
9.39.5).

package.json

@@ -10,21 +10,21 @@
   },
   "dependencies": {
     "@supabase/ssr": "^0.12.1",
-    "@supabase/supabase-js": "^2.110.3",
+    "@supabase/supabase-js": "^2.110.5",
     "lucide-react": "^1.24.0",
     "next": "16.2.10",
-    "react": "19.2.4",
-    "react-dom": "19.2.4"
+    "react": "19.2.7",
+    "react-dom": "19.2.7"
   },
   "devDependencies": {
-    "@types/node": "^20",
-    "@types/react": "^19",
-    "@types/react-dom": "^19",
-    "autoprefixer": "^10.5.2",
-    "eslint": "^9",
+    "@tailwindcss/postcss": "^4.3.2",
+    "@types/node": "^24.13.3",
+    "@types/react": "^19.2.17",
+    "@types/react-dom": "^19.2.3",
+    "eslint": "^9.39.5",
     "eslint-config-next": "16.2.10",
     "postcss": "^8.5.19",
-    "tailwindcss": "^3.4.19",
-    "typescript": "^5"
+    "tailwindcss": "^4.3.2",
+    "typescript": "^5.9.3"
   }
 }