fix: remove @supabase/ssr entirely to fix MIDDLEWARE_INVOCATION_FAILED

@supabase/ssr uses __dirname internally which crashes in Vercel's Edge
runtime, causing MIDDLEWARE_INVOCATION_FAILED even without a middleware
file. Replaced with @supabase/supabase-js directly:
- Server client: manual cookie-based session restoration
- Browser client: direct createClient from supabase-js
- Admin client: already using supabase-js

https://claude.ai/code/session_01H2aRGDaKgarPvhay2HxN6Y

package-lock.json

@@ -9,7 +9,6 @@
       "version": "0.1.0",
       "dependencies": {
         "@stripe/stripe-js": "^8.7.0",
-        "@supabase/ssr": "^0.8.0",
         "@supabase/supabase-js": "^2.95.3",
         "clsx": "^2.1.1",
         "next": "^15.5.12",
@@ -1086,18 +1085,6 @@
         "node": ">=20.0.0"
       }
     },
-    "node_modules/@supabase/ssr": {
-      "version": "0.8.0",
-      "resolved": "https://registry.npmjs.org/@supabase/ssr/-/ssr-0.8.0.tgz",
-      "integrity": "sha512-/PKk8kNFSs8QvvJ2vOww1mF5/c5W8y42duYtXvkOSe+yZKRgTTZywYG2l41pjhNomqESZCpZtXuWmYjFRMV+dw==",
-      "license": "MIT",
-      "dependencies": {
-        "cookie": "^1.0.2"
-      },
-      "peerDependencies": {
-        "@supabase/supabase-js": "^2.76.1"
-      }
-    },
     "node_modules/@supabase/storage-js": {
       "version": "2.95.3",
       "resolved": "https://registry.npmjs.org/@supabase/storage-js/-/storage-js-2.95.3.tgz",
@@ -2496,19 +2483,6 @@
       "dev": true,
       "license": "MIT"
     },
-    "node_modules/cookie": {
-      "version": "1.1.1",
-      "resolved": "https://registry.npmjs.org/cookie/-/cookie-1.1.1.tgz",
-      "integrity": "sha512-ei8Aos7ja0weRpFzJnEA9UHJ/7XQmqglbRwnf2ATjcB9Wq874VKH9kfjjirM6UhU2/E5fFYadylyhFldcqSidQ==",
-      "license": "MIT",
-      "engines": {
-        "node": ">=18"
-      },
-      "funding": {
-        "type": "opencollective",
-        "url": "https://opencollective.com/express"
-      }
-    },
     "node_modules/cross-spawn": {
       "version": "7.0.6",
       "resolved": "https://registry.npmjs.org/cross-spawn/-/cross-spawn-7.0.6.tgz",