Merge latest master into manual compaction

# Conflicts:
#	apps/cli/README.i18n.yaml
#	docs/architecture.i18n.yaml
#	docs/event-producer-consumer.md
#	docs/module-graph.md
#	examples/acp-agent/tests/snapshots/cordis-inspect-jsdoc/session.jsonl
#	packages/compact/compact-basic/README.i18n.yaml
#	packages/pty/pty-local/tests/index.spec.ts

docs/core-data-structures/approval.i18n.yaml

@@ -1,6 +1,6 @@
 # Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
-#   pnpm run verify-translation-pairing --write
-approval.md: 0de13eb1504b5ecc4ac0eafefefa2c87562c89b4
-approval.zh.md: b7ba10449fccfdb0dd5b52374e14038e3ec76ff8
+#   pnpm run verify-translation-pairing --write docs/core-data-structures/approval.md
+approval.md: f1889b25e2bbbcb157b0bced070b1f157a867504
+approval.zh.md: c460ec2cb847a9e9a3e772987830b58e93fc3715

docs/core-data-structures/approval.md

@@ -42,13 +42,12 @@ type ApprovalOutcome = 'allowed-once' | 'rejected' | 'cancelled' | 'unavailable'
  *   (exactly today's behavior).
  * - `'never'` — never prompt anyone: every ask resolves `'rejected'`
  *   deterministically. The strict headless stance (CI, unattended runs) and
- *   the only policy value stated in the system prompt — unlike `'ask'`, its
- *   outcome is knowable without asking, so stating it cannot overclaim.
+ *   the policy whose outcome is knowable without asking.
  */
 type ApprovalPolicy = 'ask' | 'never'
 ```
 
-The prompt section states the deterministic `never` behavior and records either policy with a source-owned marker. The pre-step narrator reads that marker from the logged request header after restart; it does not infer state from deployment persona prose.
+Both policies contribute their complete current meaning to the cache-safe runtime-context snapshot. The sourced `user/message` is the durable model-visible input; changing approval state appends a new full snapshot after retained history without rewriting the request header's system prompt.
 
 ## Approval request
 
@@ -87,4 +86,4 @@ interface ApprovalRequest {
 
 `ctx.approval.request(req)` requires the requesting session to be inside an open turn. It appends `approval/asked`, obtains one outcome, appends the matching `approval/decided`, and resolves with that outcome. The `never` policy is enforced inside the service before waterfall dispatch, so even an answerer registered later with `prepend` cannot bypass it. Answerers return an outcome when they own the request or call `next()` to delegate; the first answer occupies the single decision slot.
 
-The audit events are log-only and do not enter the model transcript. Model-visible behavior is the caller's derived tool result, while the request header records the prompt policy that the model actually saw. Service disposal removes its prompt section and pre-step narrator together; answerer listeners are independently effect-bound to their owning plugins.
+The audit events are log-only and do not enter the model transcript. Model-visible behavior is the caller's derived tool result plus the current runtime-context snapshot. Service disposal removes its context contribution; answerer listeners are independently effect-bound to their owning plugins.

docs/core-data-structures/approval.zh.md

@@ -42,13 +42,12 @@ type ApprovalOutcome = 'allowed-once' | 'rejected' | 'cancelled' | 'unavailable'
  *   (exactly today's behavior).
  * - `'never'` — never prompt anyone: every ask resolves `'rejected'`
  *   deterministically. The strict headless stance (CI, unattended runs) and
- *   the only policy value stated in the system prompt — unlike `'ask'`, its
- *   outcome is knowable without asking, so stating it cannot overclaim.
+ *   the policy whose outcome is knowable without asking.
  */
 type ApprovalPolicy = 'ask' | 'never'
 ```
 
-提示词段落会声明 `never` 的确定性行为，并以服务自有的标记记录当前策略。重启后，步骤前叙述器从已记录的请求头中读取该标记，而非从部署 persona 行文中推断状态。
+两种策略都会将各自完整的当前含义贡献给缓存安全的运行时上下文快照。带来源的 `user/message` 是持久化且模型可见的输入；批准状态变化时，会在保留的历史后追加一份新的完整快照，而不改写请求头中的系统提示词。
 
 ## 审批请求
 
@@ -87,4 +86,4 @@ interface ApprovalRequest {
 
 `ctx.approval.request(req)` 要求发起请求的会话处于一个打开的轮次内。它追加 `approval/asked`，获取一个结果，追加对应的 `approval/decided`，然后以该结果 resolve。`never` 策略在服务内部、waterfall 分发之前强制执行，因此即使后来以 `prepend` 注册的应答者也无法绕过它。应答者在拥有该请求时返回结果，否则调用 `next()` 委托；第一个应答占据唯一的决策槽位。
 
-审计事件仅写入日志，不进入模型 transcript（文本记录）。模型可见的行为是调用方派生的工具结果，而请求头记录的是模型实际看到的提示词策略。服务 dispose（资源释放）时会一并移除其提示词段落和步骤前叙述器；应答者监听器独立地通过 effect 绑定到其所属插件。
+审计事件仅写入日志，不进入模型 transcript（文本记录）。模型可见的行为是调用方派生的工具结果与当前运行时上下文快照。服务 dispose（资源释放）时会移除其上下文贡献；应答者监听器独立地通过 effect 绑定到其所属插件。

docs/core-data-structures/llm-streaming.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/core-data-structures/llm-streaming.md
-llm-streaming.md: e7500a7985ea1916e206c41e05855701b48fcf00
-llm-streaming.zh.md: 2b61815f2730afdfb93bc06b8ee8925d2f4cac25
+llm-streaming.md: 28f775f81049d3aa0198e75fbb6c4544302e772d
+llm-streaming.zh.md: 76282018f0cfa119199e221985bd09eaac69c839

docs/core-data-structures/llm-streaming.md

@@ -162,13 +162,15 @@ declare class BlockAssembler {
 
 ## The seam
 
-`LlmAdapter` is the provider seam: subclass, implement `stream()`, and register one adapter instance with `ctx.llm.registerAdapter(providers, adapter)`. `GenerateOptions.provider` selects the registered adapter; `GenerateOptions.model` is passed to that adapter and need not be registered at lifecycle start. Duplicate provider routes fail atomically. Optional `providerRetryPolicy()` is captured per route with normal defaults, while `providerInfo()` and asynchronous `listModels()` feed `LlmService.listProviders()` / `listModels()` with detached selector metadata. That catalog is advisory rather than a request whitelist: the adapter remains authoritative and may accept unlisted model ids. One asynchronous `resolveModel()` query returns exact model identity plus optional correctness-sensitive context capacity, an adapter-configured `defaultMaxTokens`, and ordered model-owned reasoning ids with an optional deployment default; absent fields mean unavailable metadata or provider-owned behavior, not invalid catalog membership. The resolver receives optional cancellation and must settle promptly after abort. `LlmService.resolveModelInfo()` validates and detaches the aggregate. At the final adapter boundary, `resolveCallConfig()` materializes the output default only when `maxTokens` is absent and validates and materializes reasoning, so direct calls cannot bypass either configured behavior; direct dispatch captures one registration before awaiting that resolution. The agent loop instead uses `prepareCall()` to keep the same registration across model resolution, durable header logging, and dispatch. Adapter lookup happens at the terminal continuation of the `llm/stream` waterfall, so a listener may short-circuit the call or route a mutable one-shot request before lookup. The `block-start` / `block-end` `index` correlation and the assembler together mean an adapter only has to emit well-formed chunks — block reassembly is not each adapter's problem. The consumer surface (`ctx.llm.stream()`) and the `llm/stream` waterfall are described in [architecture.md § Content blocks and streaming](../architecture.md#content-blocks-and-streaming-dsh-llm).
+`LlmAdapter` is the provider seam: subclass, implement `stream()`, and register one adapter instance with `ctx.llm.registerAdapter(providers, adapter)`. `GenerateOptions.provider` selects the registered adapter; `GenerateOptions.model` is passed to that adapter and need not be registered at lifecycle start. Duplicate provider routes fail atomically. Optional `providerRetryPolicy()` is captured per route with normal defaults, while `providerInfo()` and asynchronous `listModels()` feed `LlmService.listProviders()` / `listModels()` with detached selector metadata. That catalog is advisory rather than a request whitelist: the adapter remains authoritative and may accept unlisted model ids. One asynchronous `resolveModel()` query returns exact model identity plus optional correctness-sensitive context capacity, an adapter-configured `defaultMaxTokens`, and ordered model-owned reasoning ids with an optional deployment default; absent fields mean unavailable metadata or provider-owned behavior, not invalid catalog membership. The resolver receives optional cancellation and must settle promptly after abort. `LlmService.resolveModelInfo()` validates and detaches the aggregate. At the final adapter boundary, `resolveCallConfig()` materializes the output default only when `maxTokens` is absent and validates and materializes reasoning, so direct calls cannot bypass either configured behavior; direct dispatch captures one registration before awaiting that resolution. The agent loop instead uses `prepareCall()` to keep the same registration across model resolution, durable header logging, and dispatch, retain detached context metadata from that exact lookup, and report which config fields the adapter defaulted. Adapter lookup happens at the terminal continuation of the `llm/stream` waterfall, so a listener may short-circuit the call or route a mutable one-shot request before lookup. AgentLoop observes a request attempt once the outer waterfall returns a stream handle; that limited boundary does not prove a lazy terminal adapter was constructed or began provider I/O. The `block-start` / `block-end` `index` correlation and the assembler together mean an adapter only has to emit well-formed chunks — block reassembly is not each adapter's problem. The consumer surface (`ctx.llm.stream()`) and the `llm/stream` waterfall are described in [architecture.md § Content blocks and streaming](../architecture.md#content-blocks-and-streaming-dsh-llm).
 
 ```ts type-equiv
 /** One model call whose config and adapter registration were resolved together. */
 interface PreparedLlmCall {
   /** Detached, deep-frozen config with any adapter-owned default materialized. */
   readonly config: LlmCallConfig
+  /** Detached context metadata resolved with the registration-bound call. */
+  readonly context?: LlmModelContext
   /** Config fields materialized by the captured adapter rather than proposed by the caller. */
   readonly adapterDefaults: LlmCallConfigAdapterDefaults
   /**

docs/core-data-structures/llm-streaming.zh.md

@@ -162,13 +162,15 @@ declare class BlockAssembler {
 
 ## seam
 
-`LlmAdapter` 是提供方 seam：创建子类、实现 `stream()`，再用 `ctx.llm.registerAdapter(providers, adapter)` 注册一个适配器实例。`GenerateOptions.provider` 选择已注册适配器；`GenerateOptions.model` 会传给该适配器，无需在生命周期启动时注册。重复提供方路由会原子失败。可选的 `providerRetryPolicy()` 会按路由捕获并填入 normal 默认值，`providerInfo()` 与异步 `listModels()` 方法则为 `LlmService.listProviders()` / `listModels()` 提供分离的 selector 元数据。该目录仅供参考，不是请求白名单：适配器仍是权威，并可接受未列出的模型 id。单次异步 `resolveModel()` 查询返回确切模型身份，以及可选的对正确性敏感的上下文容量、适配器配置的 `defaultMaxTokens`、由模型持有的有序推理强度 ID 和部署默认值；字段缺失表示元数据不可用或保留提供方持有的行为，而不表示目录成员关系无效。解析器会接收可选的取消信号，并且必须在信号中止后迅速完成结算。`LlmService.resolveModelInfo()` 会校验聚合结果并返回分离值。在最终适配器边界，`resolveCallConfig()` 仅在 `maxTokens` 缺失时填入输出默认值，并校验和填入推理强度，因此直接调用也无法绕过任何一项已配置行为；直接分派会在等待解析前捕获一项适配器注册。agent loop 则使用 `prepareCall()`，使模型解析、请求头持久记录和分派全程使用同一项注册。适配器查找发生在 `llm/stream` waterfall（瀑布式事件）的终端 continuation，因此 listener 可以在查找前短路调用，或路由一个可变的一次性请求。`block-start` / `block-end` 的 `index` 关联与 assembler 共同意味着适配器只需 emit 格式正确的分片——块重组不是每个适配器各自的问题。消费方 surface（`ctx.llm.stream()`）与 `llm/stream` waterfall 见 [architecture.md § 内容块与流式传输](../architecture.md#content-blocks-and-streaming-dsh-llm)。
+`LlmAdapter` 是提供方 seam：创建子类、实现 `stream()`，再用 `ctx.llm.registerAdapter(providers, adapter)` 注册一个适配器实例。`GenerateOptions.provider` 选择已注册适配器；`GenerateOptions.model` 会传给该适配器，无需在生命周期启动时注册。重复提供方路由会原子失败。可选的 `providerRetryPolicy()` 会按路由捕获并填入 normal 默认值，`providerInfo()` 与异步 `listModels()` 方法则为 `LlmService.listProviders()` / `listModels()` 提供分离的 selector 元数据。该目录仅供参考，不是请求白名单：适配器仍是权威，并可接受未列出的模型 id。单次异步 `resolveModel()` 查询返回确切模型身份，以及可选的对正确性敏感的上下文容量、适配器配置的 `defaultMaxTokens`、由模型持有的有序推理强度 ID 和部署默认值；字段缺失表示元数据不可用或保留提供方持有的行为，而不表示目录成员关系无效。解析器会接收可选的取消信号，并且必须在信号中止后迅速完成结算。`LlmService.resolveModelInfo()` 会校验聚合结果并返回分离值。在最终适配器边界，`resolveCallConfig()` 仅在 `maxTokens` 缺失时填入输出默认值，并校验和填入推理强度，因此直接调用也无法绕过任何一项已配置行为；直接分派会在等待解析前捕获一项适配器注册。agent loop 则使用 `prepareCall()`，使模型解析、请求头持久记录和分派全程使用同一项注册，保留来自同一次查询的分离上下文元数据，并报告适配器填入的配置字段。适配器查找发生在 `llm/stream` waterfall（瀑布式事件）的终端 continuation，因此 listener 可以在查找前短路调用，或路由一个可变的一次性请求。AgentLoop 在外层 waterfall 返回流句柄时观察到一次请求尝试；这个有限边界不能证明惰性终端适配器已构造完成或开始提供方 I/O。`block-start` / `block-end` 的 `index` 关联与 assembler 共同意味着适配器只需 emit 格式正确的分片——块重组不是每个适配器各自的问题。消费方 surface（`ctx.llm.stream()`）与 `llm/stream` waterfall 见 [architecture.md § 内容块与流式传输](../architecture.md#content-blocks-and-streaming-dsh-llm)。
 
 ```ts type-equiv
 /** One model call whose config and adapter registration were resolved together. */
 interface PreparedLlmCall {
   /** Detached, deep-frozen config with any adapter-owned default materialized. */
   readonly config: LlmCallConfig
+  /** Detached context metadata resolved with the registration-bound call. */
+  readonly context?: LlmModelContext
   /** Config fields materialized by the captured adapter rather than proposed by the caller. */
   readonly adapterDefaults: LlmCallConfigAdapterDefaults
   /**

docs/core-data-structures/session.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/core-data-structures/session.md
-session.md: f337a6ffb200ffbe8146ee168b1aa0c4030defe0
-session.zh.md: 1637efedbacd76cfd651badbaf699655ad8e94fb
+session.md: 6369c956df03c0d786db696c208b000300d5bfbc
+session.zh.md: c39382b7e6c9b14f91c311cc80526a6fd8898e4c

docs/core-data-structures/session.md

@@ -91,6 +91,16 @@ interface SessionEventMap {
    * It is log-only; the latest snapshot reconstructs the request header.
    */
   'request/header': { header: EpochHeader; reason: RequestHeaderReason }
+  /**
+   * Registration-bound context metadata for the route a request resolved to,
+   * appended inside its step beside `request/header` and only when the route
+   * or capacity differs from the last record. It is log-only and deliberately
+   * NOT part of {@link EpochHeader}: capacity is adapter metadata about a
+   * route, not an input the request was built from, so it must not participate
+   * in request reconstruction or header equality. `contextWindow` is absent
+   * when the route's adapter advertises no capacity.
+   */
+  'request/context': RequestContext
   /**
    * Marks the end of a constructor seed. Events before it have smaller seq
    * values and came from the seed (resume, fork, or replay); this lifecycle
@@ -168,6 +178,26 @@ interface EpochHeader {
 
 Canonical form represents an empty system prompt or tool list as an absent field, matching how requests are built. Legacy v0 logs containing the removed `request/header-delta` event or its full-snapshot `fallback` reason are rejected at seed, append, and persistence-load boundaries rather than replayed incompletely.
 
+### The route capacity event: `request/context`
+
+The context metadata of the route a request resolved to is separate logged state, appended beside `request/header` inside the same step and only when the provider, model, or capacity differs from the previous record. It stays outside `EpochHeader` because that type is the reconstruction contract compared field-wise by `headerEquals`: capacity describes a route, not a request input, so folding it in would let a capacity change register as a request-envelope `change` and would pull adapter metadata into the loop's reconstruction invariant. Like `request/header`, it is not a `SurfaceEventType` and produces no LLM message. `session.requestContext()` folds the latest record incrementally. A route whose adapter advertises no capacity is recorded with `contextWindow` absent, so the new record clears an older route's capacity.
+
+```ts type-equiv
+/**
+ * Registration-bound context metadata of one resolved model route. Adapter
+ * metadata about a route rather than a request input, which is why it lives
+ * outside {@link EpochHeader}.
+ */
+interface RequestContext {
+  /** Registered provider route the metadata was resolved through. */
+  provider: string
+  /** Provider-owned model id the metadata belongs to. */
+  model: string
+  /** Maximum combined request and response context in tokens; absent when the adapter advertises none. */
+  contextWindow?: number
+}
+```
+
 ## `SessionEvent<T>` — one log entry
 
 A proper discriminated union over `type` (not independent `type`/`data` unions), so `switch (event.type)` narrows `event.data` without casts. `seq` is the monotonic position in the log (`seq = log.length`); `time` is epoch ms.
@@ -429,6 +459,14 @@ declare class Session {
    * @returns the folded header, or undefined when no header event exists yet.
    */
   requestHeader(): EpochHeader | undefined;
+  /**
+   * The route metadata in force after the log's last `request/context` event —
+   * what the NEXT request deduplicates against — or undefined before any such
+   * record. Maintained incrementally like {@link requestHeader}, so a per-step
+   * read costs O(new events).
+   * @returns the folded context record, or undefined when none exists yet.
+   */
+  requestContext(): RequestContext | undefined;
   /**
    * Derive the LLM message history by walking the ordered sequences of
    * message-producing events maintained by `surfaceOp` markers. The

docs/core-data-structures/session.zh.md

@@ -91,6 +91,16 @@ interface SessionEventMap {
    * It is log-only; the latest snapshot reconstructs the request header.
    */
   'request/header': { header: EpochHeader; reason: RequestHeaderReason }
+  /**
+   * Registration-bound context metadata for the route a request resolved to,
+   * appended inside its step beside `request/header` and only when the route
+   * or capacity differs from the last record. It is log-only and deliberately
+   * NOT part of {@link EpochHeader}: capacity is adapter metadata about a
+   * route, not an input the request was built from, so it must not participate
+   * in request reconstruction or header equality. `contextWindow` is absent
+   * when the route's adapter advertises no capacity.
+   */
+  'request/context': RequestContext
   /**
    * Marks the end of a constructor seed. Events before it have smaller seq
    * values and came from the seed (resume, fork, or replay); this lifecycle
@@ -170,6 +180,26 @@ interface EpochHeader {
 
 规范形式：空系统提示词和空工具列表都表示为字段缺失，与请求构建方式一致。包含已移除的 `request/header-delta` 事件或完整快照原因为 `fallback` 的旧版 v0 日志，会在 seed、append 和持久化加载边界被拒绝，而不会以不完整方式回放。
 
+### 路由容量事件：`request/context`
+
+请求所解析到的路由的上下文元数据是独立的已记录状态，在同一步骤内紧随 `request/header` 追加，且仅在提供方、模型或容量与上一条记录不同时追加。它保持在 `EpochHeader` 之外，因为该类型是由 `headerEquals` 逐字段比较的重建契约：容量描述的是路由，不是请求输入，把它折叠进去会让一次容量变化被登记为请求信封的 `change`，也会把适配器元数据拉进 loop 的重建不变式。与 `request/header` 一样，它不是 `SurfaceEventType`，也不产生 LLM 消息。`session.requestContext()` 以增量方式归并最新一条记录。适配器不公布容量的路由会以缺失 `contextWindow` 的形式记录，因此新记录可以清除较早路由的容量。
+
+```ts type-equiv
+/**
+ * Registration-bound context metadata of one resolved model route. Adapter
+ * metadata about a route rather than a request input, which is why it lives
+ * outside {@link EpochHeader}.
+ */
+interface RequestContext {
+  /** Registered provider route the metadata was resolved through. */
+  provider: string
+  /** Provider-owned model id the metadata belongs to. */
+  model: string
+  /** Maximum combined request and response context in tokens; absent when the adapter advertises none. */
+  contextWindow?: number
+}
+```
+
 ## `SessionEvent<T>`：一条日志条目
 
 基于 `type` 的真正可辨识联合（而非独立的 `type`/`data` 联合），因此 `switch (event.type)` 能直接收窄 `event.data`，无需类型断言。`seq` 是日志中的单调递增位置（`seq = log.length`）；`time` 为 epoch 毫秒。
@@ -431,6 +461,14 @@ declare class Session {
    * @returns the folded header, or undefined when no header event exists yet.
    */
   requestHeader(): EpochHeader | undefined;
+  /**
+   * The route metadata in force after the log's last `request/context` event —
+   * what the NEXT request deduplicates against — or undefined before any such
+   * record. Maintained incrementally like {@link requestHeader}, so a per-step
+   * read costs O(new events).
+   * @returns the folded context record, or undefined when none exists yet.
+   */
+  requestContext(): RequestContext | undefined;
   /**
    * Derive the LLM message history by walking the ordered sequences of
    * message-producing events maintained by `surfaceOp` markers. The

docs/core-data-structures/system-prompt.i18n.yaml

@@ -1,6 +1,6 @@
 # Bilingual-pair consistency record (docs/i18n/README.md): the git blob hash of each
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
-#   pnpm run verify-translation-pairing --write
-system-prompt.md: 63a750c74300b4353f132d3dae9da52a10631f23
-system-prompt.zh.md: 3f7ab9aee5743616f00e95e81fb9a3a4af2c6e8a
+#   pnpm run verify-translation-pairing --write docs/core-data-structures/system-prompt.md
+system-prompt.md: 5abb8f46c13045c7d37bbe12ecf6c3744ee063b5
+system-prompt.zh.md: 1088b20ba4289ad5912a193eead39d069c1a6e17

docs/core-data-structures/system-prompt.md

@@ -60,3 +60,23 @@ interface PromptSection {
   readonly text: string | ((context: AssembleContext) => string)
 }
 ```
+
+## Dynamic prompt context
+
+`PromptContext` is the cache-safe counterpart to `PromptSection`. The assembly resolves and orders these contributions, while agent-loop logs their complete current snapshot after retained model history only when it changed or compaction removed it.
+
+```ts type-equiv
+/**
+ * One dynamic model-context contribution. Unlike a {@link PromptSection}, its
+ * rendered text is materialized as a durable user-role snapshot at the request
+ * tail, so changing runtime state preserves the stable system/history prefix.
+ */
+interface PromptContext {
+  /** Unique name — a duplicate registration throws (see {@link SystemPrompt.context}). */
+  readonly name: string
+  /** Contexts are joined in ascending order, independently of system-section order. */
+  readonly order: number
+  /** Static text or a provider evaluated for each assembly. Empty text contributes nothing. */
+  readonly text: string | ((context: AssembleContext) => string)
+}
+```

docs/core-data-structures/system-prompt.zh.md

@@ -60,3 +60,23 @@ interface PromptSection {
   readonly text: string | ((context: AssembleContext) => string)
 }
 ```
+
+## 动态提示词上下文
+
+`PromptContext` 是与 `PromptSection` 对应的缓存安全结构。组装会解析这些贡献并排序；agent loop（智能体循环）仅在完整当前快照发生变化或被压缩（compaction）移除时，才会将其记录在保留的模型历史之后。
+
+```ts type-equiv
+/**
+ * One dynamic model-context contribution. Unlike a {@link PromptSection}, its
+ * rendered text is materialized as a durable user-role snapshot at the request
+ * tail, so changing runtime state preserves the stable system/history prefix.
+ */
+interface PromptContext {
+  /** Unique name — a duplicate registration throws (see {@link SystemPrompt.context}). */
+  readonly name: string
+  /** Contexts are joined in ascending order, independently of system-section order. */
+  readonly order: number
+  /** Static text or a provider evaluated for each assembly. Empty text contributes nothing. */
+  readonly text: string | ((context: AssembleContext) => string)
+}
+```