feat(channels/qq_obv11): OneBot v11 渠道插件（正/反 WS 双模式 + CQ 媒体 + 限频，stdlib 自研 WS）

plugins/channels/qq_obv11/ratelimit.go

@@ -0,0 +1,52 @@
+package qq_obv11
+
+// This file implements the sliding-window send rate limiter that keeps QQ
+// OneBot proactive/reply traffic from bursting (see DevDocs/design/08 section
+// 3, "注意风控").
+
+import (
+	"errors"
+	"sync"
+	"time"
+)
+
+// ErrRateLimited is returned by SendMessage/SendProactive when the configured
+// per-window send quota is exhausted.
+var ErrRateLimited = errors.New("qq-obv11: send rate limit exceeded")
+
+// rateLimiter enforces a maximum number of events within a sliding window. It
+// is disabled when max is non-positive.
+type rateLimiter struct {
+	max    int
+	window time.Duration
+	mu     sync.Mutex
+	times  []time.Time
+}
+
+func newRateLimiter(max int, window time.Duration) *rateLimiter {
+	return &rateLimiter{max: max, window: window}
+}
+
+// allow records a send at now and reports whether it fits within the window
+// quota. A disabled limiter (max <= 0) always allows. The timestamp is only
+// recorded when the send is accepted.
+func (r *rateLimiter) allow(now time.Time) bool {
+	if r == nil || r.max <= 0 {
+		return true
+	}
+	r.mu.Lock()
+	defer r.mu.Unlock()
+
+	cutoff := now.Add(-r.window)
+	i := 0
+	for i < len(r.times) && !r.times[i].After(cutoff) {
+		i++
+	}
+	r.times = r.times[i:]
+
+	if len(r.times) >= r.max {
+		return false
+	}
+	r.times = append(r.times, now)
+	return true
+}