chore(env): restore .env.example template and ignore accidental 'env (N)' files; remove tracked 'env (1)'

.env.example

@@ -0,0 +1,28 @@
+NODE_ENV=development
+
+# Public app URL
+NEXT_PUBLIC_APP_URL=http://localhost:3000
+
+# Better Auth
+BETTER_AUTH_URL=http://localhost:3000
+BETTER_AUTH_SECRET=change-me-in-prod
+
+# Convex (dev server URL)
+NEXT_PUBLIC_CONVEX_URL=http://127.0.0.1:3210
+
+# SQLite database (local dev)
+DATABASE_URL=file:./prisma/db.dev.sqlite
+
+# Optional SMTP (dev)
+# SMTP_ADDRESS=localhost
+# SMTP_PORT=1025
+# SMTP_TLS=false
+# SMTP_USERNAME=
+# SMTP_PASSWORD=
+# SMTP_AUTHENTICATION=login
+# SMTP_ENABLE_STARTTLS_AUTO=false
+# MAILER_SENDER_EMAIL=no-reply@example.com
+
+# Dev-only bypass to simplify local testing (do NOT enable in prod)
+# DEV_BYPASS_AUTH=0
+# NEXT_PUBLIC_DEV_BYPASS_AUTH=0