feat: add Kiro OAuth web, rate limiter, metrics, fingerprint, background refresh and model converter

internal/auth/kiro/rate_limiter_singleton.go

@@ -0,0 +1,46 @@
+package kiro
+
+import (
+	"sync"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+var (
+	globalRateLimiter     *RateLimiter
+	globalRateLimiterOnce sync.Once
+
+	globalCooldownManager     *CooldownManager
+	globalCooldownManagerOnce sync.Once
+	cooldownStopCh            chan struct{}
+)
+
+// GetGlobalRateLimiter returns the singleton RateLimiter instance.
+func GetGlobalRateLimiter() *RateLimiter {
+	globalRateLimiterOnce.Do(func() {
+		globalRateLimiter = NewRateLimiter()
+		log.Info("kiro: global RateLimiter initialized")
+	})
+	return globalRateLimiter
+}
+
+// GetGlobalCooldownManager returns the singleton CooldownManager instance.
+func GetGlobalCooldownManager() *CooldownManager {
+	globalCooldownManagerOnce.Do(func() {
+		globalCooldownManager = NewCooldownManager()
+		cooldownStopCh = make(chan struct{})
+		go globalCooldownManager.StartCleanupRoutine(5*time.Minute, cooldownStopCh)
+		log.Info("kiro: global CooldownManager initialized with cleanup routine")
+	})
+	return globalCooldownManager
+}
+
+// ShutdownRateLimiters stops the cooldown cleanup routine.
+// Should be called during application shutdown.
+func ShutdownRateLimiters() {
+	if cooldownStopCh != nil {
+		close(cooldownStopCh)
+		log.Info("kiro: rate limiter cleanup routine stopped")
+	}
+}