fix(channel,user): owner 车道只认白名单，堵住群主/伪造 role 冒充主人（裁决 06.4.2/06.4.3/06.4.4）

- 适配器只描述平台身份：qq_obv11 的 owner/admin 一律上报 RoleMember，不再上报 RoleOwner
- session 层唯一判主点只认白名单（owner.yaml Accounts ∪ 每渠道 adminIds），nil 档案 fail-closed 拒绝
- 新增「每渠道管理员层」：channels.json ChannelAccount.adminIds[] → runtimeconfig.AdminIDs → OwnerProfile.SetPlatformAdmins（整体替换语义，热重载后移除的 id 立即失效）
- 组合根接线：启动即播种、面板保存先灌白名单再重载适配器（cmd/cyrene/wire_channels.go + 4 条端到端单测）
- 06.4.3 节流与参与度状态按会话独立计数（ConversationKey 三处统一，空会话 GC）；06.4.4 未知平台主动发言保守默认 1 条/分钟

internal/services/channelbridge/flowgate.go

@@ -14,8 +14,10 @@ import (
 
 // gateFor returns the per-account flow gate for an adapter, building it lazily
 // from the adapter's Config snapshot on first use. Gates are keyed by the adapter
-// name so every account (platform:confId) gets an independent rate limit and
-// pending-cap (design/12 §6 策略三/四), and they survive adapter reconnects.
+// name so every account (platform:confId) keeps its own gate that survives adapter
+// reconnects; **the throttling counters inside a gate are per conversation**
+// (adapter.ConversationKey: platform+channelID+groupID/peerID), so two groups never
+// squeeze each other (design/12 §6 策略三/四, 裁决 06.4.3).
 func (b *Bridge) gateFor(a adapter.PlatformAdapter) *adapter.FlowGate {
 	name := a.Name()
 	b.gateMu.Lock()