fix: align admin behavior and Kratos integrations

internal/data/cache.go

@@ -22,14 +22,14 @@ type cacheStore struct {
 	memory map[string]memoryCacheEntry
 }
 
+const maxMemoryCacheEntries = 10000
+
 func NewCache(data *Data) biz.Cache {
 	return &cacheStore{data: data, memory: make(map[string]memoryCacheEntry)}
 }
 
 func (s *cacheStore) client() *redis.Client {
-	s.data.mu.RLock()
-	defer s.data.mu.RUnlock()
-	return s.data.redis
+	return s.data.redis.load()
 }
 
 func (s *cacheStore) Get(ctx context.Context, key string) (string, bool, error) {
@@ -62,6 +62,7 @@ func (s *cacheStore) Set(ctx context.Context, key, value string, expiration time
 	}
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	s.makeMemoryRoom(key)
 	entry := memoryCacheEntry{value: value}
 	if expiration > 0 {
 		entry.expiresAt = time.Now().Add(expiration)
@@ -95,6 +96,7 @@ func (s *cacheStore) Increment(ctx context.Context, key string, expiration time.
 	}
 	s.mu.Lock()
 	defer s.mu.Unlock()
+	s.makeMemoryRoom(key)
 	entry, ok := s.memory[key]
 	if ok && !entry.expiresAt.IsZero() && time.Now().After(entry.expiresAt) {
 		ok = false
@@ -111,3 +113,27 @@ func (s *cacheStore) Increment(ctx context.Context, key string, expiration time.
 	s.memory[key] = entry
 	return value, nil
 }
+
+func (s *cacheStore) makeMemoryRoom(incoming string) {
+	if len(s.memory) < maxMemoryCacheEntries {
+		return
+	}
+	now := time.Now()
+	for key, entry := range s.memory {
+		if !entry.expiresAt.IsZero() && now.After(entry.expiresAt) {
+			delete(s.memory, key)
+		}
+	}
+	if len(s.memory) < maxMemoryCacheEntries {
+		return
+	}
+	if _, exists := s.memory[incoming]; exists {
+		return
+	}
+	// The in-memory store is only a Redis fallback. A bounded arbitrary eviction
+	// is preferable to unbounded growth under IP churn.
+	for key := range s.memory {
+		delete(s.memory, key)
+		break
+	}
+}