fix: update Turnstile environment variable name

- Change TURNSTILE_SECRET_KEY to TURNSTILE_SECRET to match server .env
- Update config loading to use correct environment variable
- Update .env.example for consistency

go-backend/.env.example

@@ -69,7 +69,7 @@ SOCIAL_RECOVERY_SHARES=5
 SOCIAL_RECOVERY_DELAY_HOURS=24
 
 # Cloudflare Turnstile Configuration
-TURNSTILE_SECRET_KEY=your_turnstile_secret_key_here
+TURNSTILE_SECRET=your_turnstile_secret_key_here
 
 # AI Moderation System
 MODERATION_ENABLED=true

go-backend/internal/config/config.go

@@ -77,7 +77,7 @@ func LoadConfig() *Config {
 		R2SecretKey:             getEnv("R2_SECRET_KEY", ""),
 		R2MediaBucket:           getEnv("R2_MEDIA_BUCKET", "sojorn-media"),
 		R2VideoBucket:           getEnv("R2_VIDEO_BUCKET", "sojorn-videos"),
-		TurnstileSecretKey:      getEnv("TURNSTILE_SECRET_KEY", ""),
+		TurnstileSecretKey:      getEnv("TURNSTILE_SECRET", ""),
 	}
 }