docs(architecture): rewrite Runtime Host and define Peer Mesh contracts

ARCHITECTURE.md

@@ -21,7 +21,7 @@
 
 # Maka Backend Architecture
 
-Maka has one execution authority: Runtime Host. Desktop, TUI, CLI, bots, and evaluation clients ask Runtime Host to execute work; none owns a second Runtime.
+Each State Root has its own Runtime Host as execution and write authority. Desktop, TUI, CLI, bots, and evaluation clients execute work through that Host boundary rather than creating a second Runtime for the same state. Multiple Hosts may own different State Roots; Peer Mesh supplies endpoint membership and connections without combining their execution authorities.
 
 ```mermaid
 flowchart LR
@@ -76,6 +76,8 @@ The result kernel contains only score, normalized usage, attributable cost, dura
 
 ## Reading paths
 
+- Host ownership, admission, observation, Client isolation and lifecycle: [Runtime Host architecture](./docs/architecture/runtime-host-architecture.md).
+- Network identity, membership, path selection and stream recovery: [Peer Mesh architecture](./docs/architecture/peer-mesh-architecture.md).
 - Runtime facts and projections: [Runtime core](./docs/architecture/runtime-core-architecture-draft.md) and [compaction](./docs/architecture/llm-compaction-events-log-projection-draft.md).
 - Crash recovery and continuation: [Runtime resume](./docs/architecture/runtime-resume-architecture.md).
 - Multi-agent scheduling: [Agent Graph](./docs/architecture/agent-graph-stream-scheduling-draft.md).

ARCHITECTURE.zh-CN.md

@@ -21,7 +21,7 @@
 
 # Maka 后端架构
 
-Maka 只有一个执行 authority：Runtime Host。Desktop、TUI、CLI、bot 和 Eval client 都请求 Runtime Host 执行工作，不再拥有第二套 Runtime。
+每个 State Root 的执行与写入 authority 归属于其 Runtime Host。Desktop、TUI、CLI、bot 和 Eval client 都经过 Host 边界执行工作，不为同一份状态创建第二套 Runtime。多个 Host 可以分别拥有不同的 State Root；Peer Mesh 提供端点间的成员关系与连接，不合并这些执行 authority。
 
 ```mermaid
 flowchart LR
@@ -76,6 +76,8 @@ continuation = Maka subject 内部的 Runtime Host 行为
 
 ## 阅读路径
 
+- Host 权责、准入、观察、Client 隔离与生命周期：[Runtime Host 架构](./docs/architecture/runtime-host-architecture.zh-CN.md)。
+- 网络身份、成员关系、路径选择与 stream 恢复：[Peer Mesh 架构](./docs/architecture/peer-mesh-architecture.zh-CN.md)。
 - Runtime 事实与 projection：[Runtime core](./docs/architecture/runtime-core-architecture-draft.zh-CN.md) 与 [compaction](./docs/architecture/llm-compaction-events-log-projection-draft.zh-CN.md)。
 - Crash recovery 与 continuation：[Runtime resume](./docs/architecture/runtime-resume-architecture.zh-CN.md)。
 - Multi-agent scheduling：[Agent Graph](./docs/architecture/agent-graph-stream-scheduling-draft.zh-CN.md)。

docs/README.md

@@ -59,6 +59,7 @@ This page is the authority map for Maka documentation. Code and contract tests r
 - [WorkHub Coordination Session ADR](./architecture/workhub-coordination-session-adr.md)
 - [Runtime resume architecture](./architecture/runtime-resume-architecture.md) ([中文](./architecture/runtime-resume-architecture.zh-CN.md))
 - [Runtime Host architecture](./architecture/runtime-host-architecture.md) ([中文](./architecture/runtime-host-architecture.zh-CN.md))
+- [Peer Mesh architecture](./architecture/peer-mesh-architecture.md) ([中文](./architecture/peer-mesh-architecture.zh-CN.md))
 - [Remote Runtime Host setup](./runtime-host-remote-access.md) ([中文](./runtime-host-remote-access.zh-CN.md))
 - [Runtime resume extraction ledger](./architecture/runtime-resume-extraction-ledger.zh-CN.md)
 - [Runtime resume Phase 3–4 implementation route](./architecture/runtime-resume-phase3-phase4-workspace-checkpoint-design.zh-CN.md)