Module contracts 

Flow contracts and plugin records carried by registration declarations. 注册声明携带的数据流合同与插件记录。

These are pure protocol nouns. They live in the plugin module because that is what they describe; declaration re-exports them so a declaration can keep naming them without a second copy in the tree. 这些是纯协议名词。它们住在 plugin 模块，因为描述的正是插件；declaration 再导出它们，让声明继续以原名引用，而不在树里出现第二份副本。

Structs

ContractId

A logical replacement slot. Concrete implementations keep their own node identity; the slot is the stable name that a graft targets. 逻辑替换插槽。具体实现保留各自 node identity；嫁接针对的是稳定插槽名。

FlowContract

The mechanically comparable part of a data-flow contract. 数据流合同中可以机械比较的部分。

FrameworkId

A stable host identity. Package names are not enough when several frameworks share one process. 稳定的宿主身份。同一进程存在多个框架时，crate 名称并不足以区分目标。

OwnedFlowContract

Owned flow contract used by file-backed snapshots. 文件快照使用的拥有型数据流合同。

PluginManifest

Plugin manifest metadata. 插件 manifest 元数据。

Enums

FlowSemantic

Normalized semantic labels used by tooling when string contracts are too coarse to explain a mismatch (for example local vs absolute coordinates). 调试工具使用的规范化语义标签，避免仅凭字符串无法解释坐标域差异。

PluginMode

Whether a plugin adds a new capability or replaces an existing slot. 插件是增加能力还是替换已有插槽。

PluginSource

Where the plugin came from. Trust policy is deliberately separate from registration structure and flow compatibility. 插件来源。信任策略与注册结构、数据流兼容性刻意分离。

Traits

FlowContractProvider

A handle can expose its data-flow contract once; registration faces then read it without repeating input/output strings. handle 只需声明一次数据流合同；注册面直接读取，不重复填写输入输出字符串。