Initial open source release

internal/store/ratelimit.go

@@ -0,0 +1,11 @@
+package store
+
+import (
+	"context"
+	"time"
+)
+
+// RateLimiter 提供轻量窗口限流。返回 retryAfterSeconds 供 RPC 映射 FLOOD_WAIT_X。
+type RateLimiter interface {
+	Allow(ctx context.Context, key string, limit int, window time.Duration) (allowed bool, retryAfterSeconds int, err error)
+}