Doc: Add message call behavior descriptions for nested invocation scenarios

[Copilot]

Users need clarity on CSM message behavior when calls are nested—e.g., sending async messages during sync execution, or nested sync calls forming chains.

Changes

Added "消息调用场景行为说明" section to docs/basic/communication.md covering:

• 4 invocation scenarios with behavior mechanics:

  • Sync → Async: async posts immediately, "Async Message Posted" queued after sync response
  • Sync → Sync: forms call chain (A→B→C), timeouts accumulate, deadlock warning
  • Async → Sync: receiver blocks on sync call before returning async response
  • Async → Async: fully non-blocking, response order non-deterministic

• Queue processing model: FIFO with priority lanes, execution flow visualization

• Pitfalls: circular call deadlocks, timeout accumulation in chains, response ordering assumptions

Example

// Scenario: Sync call with nested async notification
API: GetData >> params -@ Database        // Blocks until response
API: UpdateProgress >> 50% ->| UI         // Posts immediately, queued

// Scenario: Nested sync chain
API: ProcessOrder >> data -@ ModuleB
  ├─ API: ValidateUser >> id -@ ModuleC   // B blocks on C
  └─ API: CheckInventory >> id -@ ModuleD // B blocks on D

140 lines added.

Original prompt

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This section details on the original issue you should resolve

<issue_title>Doc: 添加消息调用不同场景的行为描述，更为清晰一些，例如：在同步消息执行时，发送了异步消息，会怎么样</issue_title>
<issue_description></issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Doc: 添加消息调用不同场景的行为描述，更为清晰一些，例如：在同步消息执行时，发送了异步消息，会怎么样 #3

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