feat: add configurable test mode and rate limiting

- Add TestMode, RateLimitEnabled, RequestsPerMinute to Config
- Add getEnvBool() and getEnvInt() helper functions
- Update rate limiter to support enabled/disabled state
- Pass test environment variables through docker-compose
- Configure rate limiter dynamically in main.go

This allows disabling rate limiting for integration testing while
maintaining security in production environments.

internal/middleware/rate_limiter.go

@@ -10,6 +10,7 @@ import (
 
 // RateLimiterConfig defines rate limiting configuration
 type RateLimiterConfig struct {
+	Enabled           bool
 	RequestsPerMinute int
 	CleanupInterval   time.Duration
 }
@@ -17,6 +18,7 @@ type RateLimiterConfig struct {
 // DefaultRateLimiterConfig returns sensible defaults
 func DefaultRateLimiterConfig() RateLimiterConfig {
 	return RateLimiterConfig{
+		Enabled:           true,
 		RequestsPerMinute: 10,
 		CleanupInterval:   5 * time.Minute,
 	}
@@ -98,6 +100,11 @@ func (rl *RateLimiter) Allow(ip string) bool {
 func RateLimiterMiddleware(rl *RateLimiter) echo.MiddlewareFunc {
 	return func(next echo.HandlerFunc) echo.HandlerFunc {
 		return func(c echo.Context) error {
+			// If rate limiting is disabled, skip checks
+			if !rl.config.Enabled {
+				return next(c)
+			}
+
 			// Get client IP
 			ip := c.RealIP()
 			if ip == "" {