feat: 管理面板补齐(RAG导入/记忆添加/会话接history/诚实表述) + design/16 §4.6 IM多会话隔离+第三方身份+黑白名单

agent-98 面板批次:
- 会话管理面板改接 history.ListSessions(主web+次级) + 新建次级会话按钮
- 记忆面板手动添加入口 POST /admin/memories(owner)
- 知识库真正实现 IndexDocument(分块+落projectindex) + POST /admin/rag 导入端点
- 三面板空态诚实表述(去除'后端M10+提供')
- RAG嵌入降级到keyword/line(无直属embedder,不伪造语义,符合红线)

agent-99 design/16 §4.6:
- model.Message.SenderName + 迁移0006 sender_name 列
- 第三方身份边界: session.ResolveActor判定(非LLM猜) + [第三方·昵称]前缀(不改源content)
- 群聊/陌生人落独立sess-xxx(persistIsolated),不写主会话,不广播
- 黑/白名单(allowGroups/denyGroups/allowUsers/denyUsers)最前拦截,不进LLM
- 多账号 CHANNELS_JSON 配置 + 每平台多实例
- 管理只读 GET /admin/channels/{platform}/messages(该平台非主人消息流)

实机验证(JWT): 会话管理返回主会话web / 记忆添加成功 / RAG导入documents非空+Cyrene命中; 后端build/vet/test全绿 + 前端build绿

internal/services/channelbridge/persist.go

@@ -3,6 +3,8 @@ package channelbridge
 import (
 	"context"
 
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/channel/adapter"
+	"git.yeij.top/AskaEth/Cyrene_v2/internal/channel/session"
 	"git.yeij.top/AskaEth/Cyrene_v2/internal/runtime/history"
 )
 
@@ -23,6 +25,16 @@ func (b *Bridge) SetOnPersisted(fn func(history.Message)) {
 	b.onPersisted = fn
 }
 
+// SetOnRejected wires (or replaces) the hook called after a message is dropped by
+// the allow/deny black-or-white lists (design/16 §4.6 §6). The composition root
+// routes it into the gateway audit trail. It is a no-op-safe call and is safe for
+// concurrent use with in-flight processing.
+func (b *Bridge) SetOnRejected(fn func(adapter.UnifiedMessage, string)) {
+	b.mu.Lock()
+	defer b.mu.Unlock()
+	b.onRejected = fn
+}
+
 // notifyPersisted hands a just-persisted message to the transport hook when one is
 // wired, so the gateway can broadcast `message_persisted` for cross-end sync.
 func (b *Bridge) notifyPersisted(msg history.Message) {
@@ -53,3 +65,27 @@ func (b *Bridge) persistToMain(ctx context.Context, role, content, platform, dev
 	}
 	b.notifyPersisted(full)
 }
+
+// persistIsolated writes one message into a restricted (group / stranger) session's
+// own platform log (design/16 §4.6 §4): the message lands in the isolated sess-xxx
+// session (NOT the main web session) and carries the channel platform, the client
+// deviceID and the sender's display name, so the IM adapter log page can render the
+// non-owner message stream. It is deliberately NOT broadcast to the Web main session
+// (only owner-private messages mirror to the Web). It is a no-op when no history
+// store is wired, so the bridge runs unchanged without storage.
+func (b *Bridge) persistIsolated(ctx context.Context, role, content, deviceID string, sess session.Session, platform, senderName string) {
+	if b.history == nil {
+		return
+	}
+	full, err := b.history.AppendFull(ctx, history.Message{
+		SessionID: sess.SessionID, Role: role, Content: content, Platform: platform,
+		DeviceID: deviceID, SenderName: senderName,
+	})
+	if err != nil {
+		b.log.Warn("persist isolated session", "err", err, "role", role,
+			"session", sess.SessionID, "platform", platform, "sender_name", senderName)
+		return
+	}
+	// No broadcast: third-party messages must not reach the Web main session (design/16 §4.6 §3).
+	_ = full
+}