refactor(msw): align setup with next-msw-integration pattern

- Remove instrumentation.ts (Next.js hook approach)
- Move server-side MSW init to layout.tsx using require()
- Clean up debug console.log statements from:
  - lib/supabase/server.ts
  - proxy.ts
  - app/auth/callback/route.ts
  - lib/actions/board.ts

This follows the simpler pattern from laststance/next-msw-integration
without requiring Next.js experimental features.

Author: ryota-murakami

app/auth/callback/route.ts

@@ -64,7 +64,6 @@ export async function GET(request: Request) {
           maxAge: 60 * 60 * 24 * 7, // 7 days (adjust to match GitHub token expiration)
           path: '/',
         })
-        console.log(`GitHub provider_token saved to cookie: ${cookieName}`)
       } else {
         console.warn(
           'No provider_token in session - GitHub API access may be limited',

app/layout.tsx

@@ -30,11 +30,17 @@ import { Toaster } from 'sonner'
 import { CommandPalette } from '@/components/CommandPalette/CommandPalette'
 import { ShortcutsHelp } from '@/components/ShortcutsHelp'
 import { Providers } from '@/lib/redux/providers'
+import { isMSWEnabled } from '@/lib/utils/isMSWEnabled'
 
 import { MSWProvider } from './msw-provider'
 
-// NOTE: Server-side MSW is initialized via instrumentation.ts (Next.js hook)
-// This ensures MSW starts BEFORE any route handlers run.
+// Server-side MSW initialization (runs at module load time)
+// Uses require() to avoid bundling issues with Next.js SSR
+if (process.env.NEXT_RUNTIME === 'nodejs' && isMSWEnabled()) {
+  // eslint-disable-next-line @typescript-eslint/no-require-imports
+  const { server } = require('../mocks/server')
+  server.listen({ onUnhandledRequest: 'bypass' })
+}
 
 export default function RootLayout({
   children,

instrumentation.ts

@@ -777,7 +777,5 @@ export async function createFirstBoardIfNeeded(
     // Non-critical - don't block
   }
 
-  console.log('Created first board for new user:', data.id)
-
   return { id: data.id, name: data.name }
 }

lib/actions/board.ts

@@ -67,14 +67,6 @@ export async function createClient() {
 
   // In E2E test mode, wrap auth methods to return mock data
   const testMode = isE2ETestMode()
-  console.log(
-    '[createClient] APP_ENV:',
-    process.env.APP_ENV,
-    'NODE_ENV:',
-    process.env.NODE_ENV,
-    'isE2ETestMode:',
-    testMode,
-  )
   if (testMode) {
     // Use a Proxy to intercept auth methods while preserving all other client functionality
     const mockedAuth = {

lib/supabase/server.ts

@@ -24,7 +24,6 @@ const isE2ETestMode = () =>
 export async function proxy(request: NextRequest) {
   // In E2E test mode, bypass authentication and allow all requests
   if (isE2ETestMode()) {
-    console.log('[proxy] E2E test mode - bypassing auth check')
     return NextResponse.next({
       request: {
         headers: request.headers,