feat(skill): hot-refresh skill catalogs

packages/skill/skill/README.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
-README.md: 639616d0b75f960e9ccd48546d44db841372bbe2
-README.zh.md: 3afdd415397927ebf107d6f862422c711a51888b
+#   pnpm run verify-translation-pairing --write packages/skill/skill/README.md
+README.md: f4f933576c60c8d750e3bd8eb0183ccb4b37e2da
+README.zh.md: baa0d0ca43a8da3e3177d5c05437501a1fbe1735

packages/skill/skill/README.md

@@ -11,10 +11,16 @@ This package owns the `ctx.skills` interface. It does not know whether skills co
 ### Public API
 
 - `ctx.skills.registerProvider(provider): () => void` Registers a readonly provider by unique `provider.name`. Duplicate provider names throw, and `runtime` is reserved for `ctx.skills.register(...)`. The registry borrows the provider object and invokes its methods directly. The registration is effect-scoped and HMR-safe, and the exact Cordis disposer supports ordered composite teardown.
+- `ctx.skills.invalidateProvider(provider): void` Marks one exact live provider dirty and clears completed catalog caches. Calls from a disposed or replaced provider instance are no-ops, so late watcher callbacks cannot invalidate its replacement.
+- `ctx.skills.snapshot({ cwd?, signal? })` Returns `{ skills, complete }`. `complete` is false when any provider failed transiently; incomplete observations are never cached, so a model-facing consumer can retain its last-good catalog and retry at the next request boundary.
 - `ctx.skills.list({ cwd?, signal? })` Borrows the readonly lookup options, then returns model-invocable summaries for the current workspace, merged across providers and sorted by name.
 - `ctx.skills.get(name, { cwd?, signal? })` Uses the same readonly options and winning candidate for discovery and loading, rechecks cancellation after discovery or a cache hit, races provider loading against the signal, validates the loaded definition, then returns it, including disabled-for-model skills.
 - `ctx.skills.register(skill): () => void` Registers a readonly runtime embedded skill, adding `provider: "runtime"` when omitted. Same-name runtime registrations are first-wins: a duplicate logs a warning and gets a no-op disposer. Successful registrations return the exact Cordis disposer for ordered composite teardown.
 
+### Events
+
+- `skills/change` is an unfiltered invalidation notification emitted after a provider or runtime contribution is registered or disposed and after `invalidateProvider()` accepts an exact live provider. It carries no catalog or diff: each consumer refetches `snapshot()` with its own lookup options. Listener throws and rejected promises are logged and cannot veto the registry mutation or starve later listeners.
+
 ### Config
 
 | Field | Default | Meaning |
@@ -27,7 +33,9 @@ A provider registers synchronously and performs remote setup, authentication, an
 
 The registry validates candidates before caching and definitions before returning them. The winning provider receives the same candidate and opaque `locator` it returned from `list()`, allowing backend-specific file, URL, id, or version handles. Callers and providers must preserve the readonly contract.
 
-Contract violations fail fast. A rejected `list()` is treated as a transient source failure: it is logged, skipped, and not cached. Only completed catalogs are cached; a provider or runtime revision change discards an in-flight result and retries. Duplicate names resolve by rank, provider registration order, then provider-local order. Summaries are sorted by skill name.
+Contract violations fail fast. A rejected provider `list()` is treated as a transient source failure: its entries are omitted from that observation, `complete` is false, and the result is not cached. A provider or runtime revision change discards an in-flight result and retries before returning. Duplicate names resolve by rank, provider registration order, then provider-local order. Summaries are sorted by skill name.
+
+Definitions remain progressively loaded. `get()` asks the winning provider for the body on every call rather than caching it in this registry. If the returned definition has a different name from the selected candidate, the stale selection is rejected and that exact provider is invalidated so the next snapshot rediscovers its catalog.
 
 ## Runtime Skills
 
@@ -39,15 +47,15 @@ The registry does not render model guidance or register model-facing tools. [`@d
 
 ## Model Experience
 
-Indirectly, through `dsh-tool-skill`, which renders provider summaries into the session prefix and loaded instructions into retained tool results.
+Indirectly, through `dsh-tool-skill`, which renders provider summaries into the initial session prefix or durable replacement catalog messages and loaded instructions into retained tool results.
 
 #### KV Cache effect
 
-No direct invalidation; the named consumer owns any request-prefix changes.
+No direct prompt effect. The named consumer owns initial prefix composition and append-only catalog replacements after invalidation.
 
 ## Known Limitations and Deferred Work
 
-- **Completed catalogs have no TTL or watcher invalidation** — a provider's underlying files or remote data can change without a registration revision, so a cached cwd stays stale until eviction or provider/runtime reload.
+- **Invalidation is provider-driven** — the registry has no TTL and cannot infer that an arbitrary remote source changed; each mutable provider must call `invalidateProvider()` from its own observation mechanism.
 - **Providers are queried sequentially** — one slow cooperative provider delays every provider registered after it; cancellation stops the caller's wait but cannot terminate work an uncooperative provider keeps running.
-- **A provider-list failure removes that whole source for the request** — the registry logs and skips it, with no model-visible diagnostic or partial-catalog recovery contract.
+- **An incomplete snapshot omits the failing provider in that observation** — the registry reports `complete: false`, but it does not own a last-good catalog or a per-provider diagnostic; consumers choose whether to retain earlier state.
 - **Duplicate resolution is first-wins** — later lower-priority candidates are logged and hidden; there is no API to inspect all shadowed definitions.

packages/skill/skill/README.zh.md

@@ -11,10 +11,16 @@
 ### 公开 API
 
 - `ctx.skills.registerProvider(provider): () => void` 使用唯一 `provider.name` 注册只读提供方。重复提供方名称会抛错，`runtime` 保留给 `ctx.skills.register(...)`。注册表借用提供方对象，并直接调用其方法。注册作用域绑定到 effect，可安全用于 HMR；精确的 Cordis disposer 支持有序组合拆卸。
+- `ctx.skills.invalidateProvider(provider): void` 按实例精确标脏一个活动提供方，并清除已完成目录缓存。已释放或已被替换的提供方实例调用此方法时不执行任何操作，因此延迟到达的 watcher 回调无法使其替代项失效。
+- `ctx.skills.snapshot({ cwd?, signal? })` 返回 `{ skills, complete }`。任一提供方发生瞬时失败时，`complete` 为 false；不完整观测绝不缓存，使面向模型的消费方可以保留上一份可用目录，并在下一个请求边界重试。
 - `ctx.skills.list({ cwd?, signal? })` 借用只读查找选项，然后返回当前工作区中模型可调用的摘要；这些摘要跨提供方合并，并按名称排序。
 - `ctx.skills.get(name, { cwd?, signal? })` 在发现和加载中使用同一组只读选项和胜出候选项；在发现或缓存命中后重新检查取消，让提供方加载与信号竞速，验证已加载定义，然后将其返回，包括已对模型禁用的 skill。
 - `ctx.skills.register(skill): () => void` 注册只读运行时嵌入式 skill，省略时添加 `provider: "runtime"`。同名运行时注册使用先到先得：重复项会记录警告，并获得无操作 disposer。成功注册会返回精确的 Cordis disposer，以供有序组合拆卸。
 
+### 事件
+
+- `skills/change` 是一条不带过滤条件的失效通知，在提供方或运行时贡献注册或释放后，以及 `invalidateProvider()` 接受精确活动提供方后发出。它不携带目录或 diff；每个消费方都使用自身的查找选项重新获取 `snapshot()`。监听器抛错或 Promise 拒绝会被记录，既不能否决注册表变更，也不能阻止后续监听器执行。
+
 ### 配置
 
 | 字段 | 默认值 | 含义 |
@@ -27,7 +33,9 @@
 
 注册表在缓存前验证候选项，在返回前验证定义。胜出提供方会收到同一候选项和不透明 `locator`，两者都是它从 `list()` 返回的内容，从而支持后端专用文件、URL、id 或版本句柄。调用方和提供方必须保持只读契约。
 
-契约违反会快速失败。被拒绝的 `list()` 视为瞬时来源失败：系统记录它、跳过它，并且不缓存。只缓存已完成目录；提供方或运行时修订变更会丢弃正在进行的结果并重试。重复名称按 rank、提供方注册顺序，然后按提供方本地顺序解析。摘要按 skill 名称排序。
+契约违反会快速失败。提供方 `list()` 被拒绝会视为瞬时来源失败：该次观测会省略其条目，`complete` 为 false，结果也不会缓存。提供方或运行时修订发生变更时，会丢弃正在进行的结果并重试后再返回。重复名称按 rank、提供方注册顺序，然后按提供方本地顺序解析。摘要按 skill 名称排序。
+
+定义仍采用渐进式加载。`get()` 每次调用都会向胜出提供方请求正文，而不是在此注册表中缓存正文。若返回定义的名称不同于所选候选项，系统会拒绝该陈旧选择，并使该提供方实例失效，以便下一次快照重新发现其目录。
 
 ## 运行时 Skill
 
@@ -39,15 +47,15 @@
 
 ## 模型体验
 
-通过 `dsh-tool-skill` 间接影响模型；该包将提供方摘要渲染到会话前缀中，并将已加载指令渲染到已保留工具结果中。
+通过 `dsh-tool-skill` 间接影响模型；该包将提供方摘要渲染到初始会话前缀或持久的替换目录消息中，并将已加载指令渲染到已保留工具结果中。
 
 #### KV 缓存影响
 
-不直接导致失效；指定的消费方负责其引起的任何请求前缀变更。
+不直接影响提示词。指定的消费方负责初始前缀组装，以及失效后的仅追加式目录替换。
 
 ## 已知限制与待完成工作
 
-- **已完成目录没有 TTL 或 watcher 失效机制**：提供方的底层文件或远程数据可在注册修订不变的情况下更改，因此已缓存 cwd 会保持陈旧，直到被驱逐或重新加载提供方/运行时。
+- **失效由提供方驱动**：注册表没有 TTL，无法推断任意远程来源是否已发生变化；每个可变提供方都必须由自身的观测机制调用 `invalidateProvider()`。
 - **提供方依次查询**：一个缓慢的协作提供方会延迟之后注册的所有提供方；取消会停止调用方等待，但无法终止不协作提供方持续运行的工作。
-- **提供方列表失败会移除该请求的整个来源**：注册表会记录并跳过它，不提供模型可见诊断或部分目录恢复契约。
+- **不完整快照会在该次观测中省略失败的提供方**：注册表会报告 `complete: false`，但不负责上一份可用目录或逐提供方诊断；消费方选择是否保留先前状态。
 - **重复解析使用先到先得**：系统会记录并隐藏较晚出现的低优先级候选项；不提供检查全部被遮蔽定义的 API。

packages/skill/skill/src/index.ts

@@ -87,6 +87,14 @@ export interface SkillLookupOptions {
   readonly signal?: AbortSignal | undefined
 }
 
+/** One catalog observation plus whether every registered provider completed discovery. */
+export interface SkillCatalogSnapshot {
+  /** Sorted model-invocable summaries from providers that completed. */
+  readonly skills: SkillSummary[]
+  /** Whether every registered provider completed discovery for this observation. */
+  readonly complete: boolean
+}
+
 /** Provider interface for one source of skills, such as local directories or a remote registry. */
 export interface SkillProvider {
   /** Unique provider name in the `ctx.skills` registry. */
@@ -119,6 +127,17 @@ declare module 'cordis' {
   interface Context {
     skills: SkillService
   }
+
+  interface Events {
+    /**
+     * A skill provider, runtime contribution, or provider-backed catalog may
+     * have changed. This is an unfiltered invalidation notification; consumers
+     * refetch the catalog for their own lookup options. Listener failures are
+     * contained and cannot veto the registry mutation.
+     * @mode emit
+     */
+    'skills/change'(): void
+  }
 }
 
 interface IndexedCandidate {
@@ -189,6 +208,17 @@ export class SkillService extends Service {
     return dispose
   }
 
+  /**
+   * Invalidate catalogs contributed by one currently registered provider. Exact object identity
+   * prevents a late callback from an old provider instance from invalidating its replacement.
+   * Calls for an already-unregistered provider are harmless.
+   * @param provider - exact provider instance whose external source changed.
+   */
+  invalidateProvider(provider: SkillProvider): void {
+    if (this.providers.get(provider.name)?.provider !== provider) return
+    this.invalidateCache()
+  }
+
   /**
    * Register a borrowed readonly runtime skill. Project entries outrank runtime entries, which
    * outrank user entries. Same-name runtime entries are first-wins; a duplicate logs a warning and
@@ -228,11 +258,26 @@ export class SkillService extends Service {
    * @returns sorted summaries, excluding skills disabled for model invocation.
    */
   async list(options: SkillLookupOptions = {}): Promise<SkillSummary[]> {
-    return (await this.collect(options))
-      .map(entry => entry.candidate)
-      .filter(skill => skill.disableModelInvocation !== true)
-      .map(toSummary)
-      .sort(compareSkillSummary)
+    return (await this.snapshot(options)).skills
+  }
+
+  /**
+   * Observe the current model-invocable catalog and whether all providers completed discovery.
+   * Incomplete observations are never cached, allowing consumers to retain last-good state and
+   * retry on their next request boundary.
+   * @param options - lookup options; `cwd` selects project roots and `signal` cancels discovery.
+   * @returns sorted summaries plus provider-completeness state.
+   */
+  async snapshot(options: SkillLookupOptions = {}): Promise<SkillCatalogSnapshot> {
+    const collected = await this.collect(options)
+    return {
+      skills: collected.entries
+        .map(entry => entry.candidate)
+        .filter(skill => skill.disableModelInvocation !== true)
+        .map(toSummary)
+        .sort(compareSkillSummary),
+      complete: collected.cacheable,
+    }
   }
 
   /**
@@ -247,7 +292,7 @@ export class SkillService extends Service {
     if (!isSkillName(name)) return undefined
     const collected = await this.collect(options)
     throwIfAborted(options.signal)
-    const match = collected.find(entry => entry.candidate.name === name)
+    const match = collected.entries.find(entry => entry.candidate.name === name)
     if (match === undefined) return undefined
     const definition = await waitWithAbort(
       match.provider.get(match.candidate, options),
@@ -255,17 +300,21 @@ export class SkillService extends Service {
     )
     if (definition === undefined) return undefined
     validateDefinition(definition)
+    if (definition.name !== match.candidate.name) {
+      this.invalidateProvider(match.provider)
+      return undefined
+    }
     return definition
   }
 
-  private async collect(options: SkillLookupOptions): Promise<IndexedCandidate[]> {
+  private async collect(options: SkillLookupOptions): Promise<CollectResult> {
     throwIfAborted(options.signal)
     while (true) {
       const providerRevision = this.providerRevision
       const runtimeRevision = this.runtimeRevision
       const key = collectCacheKey(options, providerRevision, runtimeRevision)
       const cached = this.collectCache.get(key)
-      if (cached !== undefined) return cached
+      if (cached !== undefined) return { entries: cached, cacheable: true }
 
       const result = await this.collectFresh(options)
       throwIfAborted(options.signal)
@@ -277,7 +326,7 @@ export class SkillService extends Service {
           this.collectCache.delete(oldest.value)
         }
       }
-      return result.entries
+      return result
     }
   }
 
@@ -339,6 +388,21 @@ export class SkillService extends Service {
   private invalidateCache(): void {
     this.providerRevision += 1
     this.collectCache.clear()
+    this.notifyChange()
+  }
+
+  /** Notify catalog observers without making their refresh work load-bearing. */
+  private notifyChange(): void {
+    for (const callback of this.ctx.events.dispatch('emit', ['skills/change'])) {
+      try {
+        const returned: unknown = callback()
+        void Promise.resolve(returned).catch((error: unknown) => {
+          this.ctx.logger.warn(`skills/change listener rejected: ${errorMessage(error)}`)
+        })
+      } catch (error: unknown) {
+        this.ctx.logger.warn(`skills/change listener threw: ${errorMessage(error)}`)
+      }
+    }
   }
 }
 

packages/skill/skill/tests/skill.spec.ts

@@ -555,7 +555,9 @@ describe('SkillService registry', () => {
         return undefined
       },
     })
-    expect((await ctx.skills.list()).map(skill => skill.name)).toEqual(['second-skill'])
+    const incomplete = await ctx.skills.snapshot()
+    expect(incomplete.skills.map(skill => skill.name)).toEqual(['second-skill'])
+    expect(incomplete.complete).toBe(false)
     expect(flakyCalls).toBe(1)
     expect((await ctx.skills.list()).map(skill => skill.name)).toEqual(['second-skill'])
     expect(flakyCalls).toBe(2)
@@ -566,6 +568,156 @@ describe('SkillService registry', () => {
     expect(flakyCalls).toBe(3)
   })
 
+  it('invalidates only the exact registered provider and ignores its late callbacks', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SkillService)
+    const provider = new MemoryProvider([memorySkill('first-skill', 'First', 10)])
+    const dispose = ctx.skills.registerProvider(provider)
+
+    expect((await ctx.skills.snapshot()).complete).toBe(true)
+    provider.replace([memorySkill('second-skill', 'Second', 10)])
+    ctx.skills.invalidateProvider(new MemoryProvider([]))
+    expect((await ctx.skills.list()).map(skill => skill.name)).toEqual(['first-skill'])
+
+    ctx.skills.invalidateProvider(provider)
+    expect((await ctx.skills.list()).map(skill => skill.name)).toEqual(['second-skill'])
+    dispose()
+
+    const replacement = new MemoryProvider([memorySkill('replacement-skill', 'Replacement', 10)])
+    ctx.skills.registerProvider(replacement)
+    expect((await ctx.skills.list()).map(skill => skill.name)).toEqual(['replacement-skill'])
+    ctx.skills.invalidateProvider(provider)
+    expect((await ctx.skills.list()).map(skill => skill.name)).toEqual(['replacement-skill'])
+    expect(replacement.listCalls).toBe(1)
+  })
+
+  it('emits catalog invalidations for live provider and runtime mutations', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SkillService)
+    const provider = new MemoryProvider([memorySkill('provider-skill', 'Provider', 10)])
+    let changes = 0
+    ctx.on('skills/change', () => { changes += 1 })
+
+    const disposeProvider = ctx.skills.registerProvider(provider)
+    expect(changes).toBe(1)
+    ctx.skills.invalidateProvider(new MemoryProvider([]))
+    expect(changes).toBe(1)
+    ctx.skills.invalidateProvider(provider)
+    expect(changes).toBe(2)
+
+    const disposeRuntime = ctx.skills.register({
+      name: 'runtime-skill',
+      description: 'Runtime',
+      source: 'runtime',
+      content: 'Runtime body.',
+    })
+    expect(changes).toBe(3)
+    disposeRuntime()
+    expect(changes).toBe(4)
+    disposeProvider()
+    expect(changes).toBe(5)
+    ctx.skills.invalidateProvider(provider)
+    expect(changes).toBe(5)
+  })
+
+  it('contains synchronous and asynchronous catalog observer failures', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SkillService)
+    const warnings: string[] = []
+    ctx.logger.warn = ((message: unknown) => { warnings.push(String(message)) }) as typeof ctx.logger.warn
+    const disposeThrowing = ctx.on('skills/change', () => { throw new Error('observer threw') })
+    // eslint-disable-next-line @typescript-eslint/no-misused-promises -- deliberate rejection proves notification containment
+    const disposeRejecting = ctx.on('skills/change', () => Promise.reject(new Error('observer rejected')))
+    let observed = 0
+    const disposeObserver = ctx.on('skills/change', () => { observed += 1 })
+
+    const provider = new MemoryProvider([])
+    expect(() => ctx.skills.registerProvider(provider)).not.toThrow()
+    await Promise.resolve()
+    expect(observed).toBe(1)
+    expect(warnings).toEqual([
+      'skills/change listener threw: Error: observer threw',
+      'skills/change listener rejected: Error: observer rejected',
+    ])
+
+    disposeThrowing()
+    disposeRejecting()
+    disposeObserver()
+  })
+
+  it('retries an in-flight catalog invalidated by its provider', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SkillService)
+    let release: (() => void) | undefined
+    const started = Promise.withResolvers<undefined>()
+    const gate = new Promise<void>((resolve) => { release = resolve })
+    const provider = new MemoryProvider([memorySkill('stale-skill', 'Stale', 10)])
+    const originalList = provider.list.bind(provider)
+    provider.list = async (options) => {
+      if (provider.listCalls === 0) {
+        provider.listCalls += 1
+        started.resolve(undefined)
+        await gate
+        return [memorySkill('stale-skill', 'Stale', 10)]
+      }
+      return await originalList(options)
+    }
+    ctx.skills.registerProvider(provider)
+
+    const pending = ctx.skills.list()
+    await started.promise
+    provider.replace([memorySkill('fresh-skill', 'Fresh', 10)])
+    ctx.skills.invalidateProvider(provider)
+    release?.()
+
+    expect((await pending).map(skill => skill.name)).toEqual(['fresh-skill'])
+    expect(provider.listCalls).toBe(2)
+  })
+
+  it('invalidates a provider whose loaded definition changed identity', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SkillService)
+    let listCalls = 0
+    const provider: SkillProvider = {
+      name: 'renamed',
+      async list() {
+        listCalls += 1
+        return [{
+          name: 'old-name',
+          description: 'Old name',
+          provider: 'renamed',
+          source: 'test',
+          rank: 1,
+          locator: 'old-name',
+        }]
+      },
+      async get(candidate) {
+        return { ...candidate, name: 'new-name', content: 'Fresh body.' }
+      },
+    }
+    ctx.skills.registerProvider(provider)
+
+    expect(await ctx.skills.get('old-name')).toBeUndefined()
+    await ctx.skills.list()
+    expect(listCalls).toBe(2)
+  })
+
+  it('returns undefined when a discovered candidate disappears before loading', async () => {
+    const ctx = new Context()
+    await ctx.plugin(SkillService)
+    ctx.skills.registerProvider({
+      name: 'vanished-body',
+      async list() {
+        return [{ ...memorySkill('vanished-skill', 'Vanished', 10), provider: 'vanished-body' }]
+      },
+      async get() {
+        return undefined
+      },
+    })
+
+    await expect(ctx.skills.get('vanished-skill')).resolves.toBeUndefined()
+  })
+
   it('contains a provider rejection whose string coercion throws', async () => {
     const ctx = new Context()
     await ctx.plugin(SkillService)