[Channel RFC] Proto schema definitions (7 proto files)

[eanzhao]

Parent RFC: #254

Scope

本 RFC 所有跨边界类型先以 .proto 定义，遵循 AGENTS.md "先 proto 再实现" 强约束。

Proto files

1. agents/Aevatar.GAgents.Channel.Abstractions/protos/chat_activity.proto

   • ChatActivity / ConversationReference / ParticipantRef / MessageContent / AttachmentRef / AttachmentKind / ActionElement / CardBlock / MessageDisposition / ActivityType / ConversationScope / ChannelId / BotInstanceId / TransportMode

2. agents/Aevatar.GAgents.Channel.Abstractions/protos/channel_contracts.proto

   • EmitResult / ComposeCapability / ComposeContext / ChannelCapabilities / StreamingSupport / AuthContext / PrincipalKind / StreamChunk

3. agents/Aevatar.GAgents.Channel.Abstractions/protos/schedule.proto

   • ScheduleState / ProjectionVerdict

4. agents/Aevatar.GAgents.Channel.Runtime/protos/conversation_events.proto

   • ConversationTurnCompletedEvent
   • ConversationContinueRequestedEvent（actor-to-actor proactive command envelope）
   • ConversationContinueRejectedEvent
   • ConversationContinueFailedEvent（含 oneof retry_policy { google.protobuf.Empty not_retryable; int64 retry_after_ms; }）
   • ChannelBotRegistrationEntry / UserAgentCatalogEntry / DeviceRegistrationEntry（含 IsDeleted bool for tombstone retention）
   • RejectReason / FailureKind enums

5. agents/Aevatar.GAgents.Channel.Runtime/protos/session_store.proto

   • SessionState / LeaseToken
   • 注意：LeaseToken.Owner = bytes owner = 1;（Guid 16 bytes）；LeaseToken.ExpiresAt = int64 expires_at_unix_ms（不用 google.protobuf.Timestamp）

6. agents/Aevatar.GAgents.Channel.Runtime/protos/interaction_journal.proto

   • PreAckJournalEntry

7. agents/Aevatar.GAgents.Channel.Runtime/protos/payload_quarantine.proto

   • PlatformQuarantineEnvelope（metadata + encrypted_blob_ref；不含明文 raw payload）

Out of proto scope（保持 C# only）

• ResolvedAuthContext（进程内 runtime-only，禁止跨 actor / 跨网络）
• Adapter-specific native payloads: LarkCardPayload / SlackBlockKitPayload / DiscordEmbedPayload
• Interface types (IChannelTransport / IChannelOutboundPort / IBot / IMessageComposer / ITurnContext)

Acceptance

• 7 个 proto 文件生成并验证通过
• C# generated types 可编译
• proto lint CI gate 通过（protolint / buf lint）

References

• RFC §4.1 实施约束：跨边界类型 Proto 先行
• RFC §4.1.1 Proactive command events field schemas

Dependencies

• Depends on: [Channel RFC] Phase 0 infra prerequisites (DeleteAsync / EventHubs harness / secret manager) #255（IProjectionWriteDispatcher.DeleteAsync 定义影响 projector proto）

[eanzhao]

While starting #257 on top of this line, I hit a concrete layering contradiction that seems worth resolving before #256 lands.

Today #256 places ChannelBotRegistrationEntry in agents/Aevatar.GAgents.Channel.Runtime/protos/conversation_events.proto, but #257's abstraction surface consumes that type directly in at least two places from the RFC:

• IChannelTransport.InitializeAsync(ChannelBotRegistrationEntry registration, ...)
• ITurnContext.Bot : ChannelBotRegistrationEntry

That means Aevatar.GAgents.Channel.Abstractions cannot be built without either:

1. depending upward on Aevatar.GAgents.Channel.Runtime, which breaks the repo's layering rules, or
2. duplicating the same registration contract in Abstractions, which creates drift.

I think we should clarify one of these directions explicitly in #256/#257 before implementation continues:

• move the transport/bootstrap-facing registration contract needed by IChannelTransport/ITurnContext into Channel.Abstractions, or
• keep ChannelBotRegistrationEntry in Runtime, but change [Channel RFC] Core abstractions package (Aevatar.GAgents.Channel.Abstractions) #257 to depend on a narrower Abstractions-local bootstrap/descriptor type instead of the Runtime entry.

As written, the current #256/#257 split is not simultaneously satisfiable with AGENTS.md's strict dependency direction.

[eanzhao]

这是实问题，不是误报，我已经顺手在 #268 里修掉了。

问题点确实如你说的：如果 IChannelTransport.InitializeAsync(...) / ITurnContext.Bot 直接吃 ChannelBotRegistrationEntry，那 Aevatar.GAgents.Channel.Abstractions 未来就只能反向依赖 Aevatar.GAgents.Channel.Runtime，和当前仓库的分层约束冲突。

这次我把 contract 收敛成了两层：

• Channel.Abstractions 新增 ChannelBotDescriptor + ChannelTransportBinding，作为 adapter bootstrap / bot metadata 的窄边界类型
• Channel.Runtime 的 ChannelBotRegistrationEntry 改成组合 transport_binding，继续承担 runtime/readmodel/projection 语义

对应地，RFC 文档也一起收敛了：

• IChannelTransport.InitializeAsync(ChannelTransportBinding binding, ...)
• ITurnContext.Bot : ChannelBotDescriptor

这样 #257 可以只依赖 Abstractions，不需要向上依赖 Runtime，也不用复制一份 registration contract。更新已经推到 PR #268，commit 是 5c7c7f02。