perf: pin Vercel to Seoul and tighten hosted Supabase clients

.vercelignore

@@ -24,3 +24,9 @@ test-results/
 /backend/
 /supabase/
 /docs/
+/tmp/
+/artifacts/
+/scripts/
+/DESIGN.md
+/SECURITY.md
+/AGENTS.md

apps/web/integrations/supabase/client.ts

@@ -15,7 +15,19 @@ function createSupabaseBrowserClient(): SupabaseClient<Database> {
     )
   }
 
-  return createBrowserClient<Database>(supabaseUrl, supabaseAnonKey)
+  return createBrowserClient<Database>(supabaseUrl, supabaseAnonKey, {
+    isSingleton: true,
+    auth: {
+      persistSession: true,
+      autoRefreshToken: true,
+      detectSessionInUrl: true,
+    },
+    realtime: {
+      params: {
+        eventsPerSecond: 2,
+      },
+    },
+  })
 }
 
 export function getSupabaseBrowserClient(): SupabaseClient<Database> {

apps/web/lib/supabase/server.ts

@@ -39,6 +39,10 @@ export function createClientForCookieStore(
                 }
             },
         },
+        auth: {
+            persistSession: false,
+            autoRefreshToken: false,
+        },
     });
 }
 

apps/web/lib/supabase/service-role.ts

@@ -32,6 +32,12 @@ export function createSupabaseServiceRoleClient(): SupabaseClient<Database> {
     auth: {
       persistSession: false,
       autoRefreshToken: false,
+      detectSessionInUrl: false,
+    },
+    global: {
+      headers: {
+        'X-Client-Info': 'tzudong-service-role',
+      },
     },
   });
 

apps/web/tests-unit/vercel-ignore-build.test.ts

@@ -24,13 +24,15 @@ describe("Vercel ignored build branch policy", () => {
         deploymentEnabled?: Record<string, boolean>;
       };
       ignoreCommand?: string;
+      regions?: string[];
     };
 
     expect(config.git?.deploymentEnabled).toEqual({
       "*": false,
       main: true,
       develop: true,
     });
+    expect(config.regions).toEqual(["icn1"]);
     expect(config.ignoreCommand).toBe("node scripts/vercel-ignore-build.mjs");
   });
 

apps/web/vercel.json

@@ -1,6 +1,7 @@
 {
   "$schema": "https://openapi.vercel.sh/vercel.json",
   "framework": "nextjs",
+  "regions": ["icn1"],
   "installCommand": "npm ci",
   "buildCommand": "npm run build",
   "git": {