Merge branch 'codex/canonical-tool-output' into codex/code-mode-typed-results

# Conflicts:
#	docs/config-catalog.md
#	docs/cookbook/adding-a-tool.i18n.yaml
#	docs/cookbook/adding-a-tool.md
#	docs/cookbook/adding-a-tool.zh.md
#	docs/cordis-catalog/events.md
#	docs/cordis-catalog/services.md
#	docs/event-producer-consumer.md
#	packages/core/tools/tests/code-mode.spec.ts

packages/core/tools/README.md

@@ -20,24 +20,28 @@ tools:
 - `ctx.tools.get(name: string, scope?: ScopeKey): ToolDefinition | undefined` Resolution as one scope sees it (shadowing applied; a restricted-away global reads as absent) — presenters pass the calling agent so the card matches what executed.
 - `ctx.tools.schemas(scope?: ScopeKey): ToolSchema[]` Schemas of everything the scope can see (without the `execute` functions). The shipped tools' schemas are catalogued in [docs/tool-catalog.md](../../../docs/tool-catalog.md), generated by booting each tool plugin and harvesting this method (see [the tool-schema-catalog Agent Note](../../../.agents/notes/implemented/process/2026-07-02-tool-schema-catalog.md)).
 - `ctx.tools.guard(guard: ToolGuard): () => void` Register a monotonic synchronous execution guard after `tools/pre-execute`: returning a reason denies the call, while `undefined` leaves it unchanged. A plain-context guard applies globally; an `agent.ctx` guard applies only to that agent. Later waterfall listeners cannot turn a guard denial back into permission. Disposed with the calling fiber.
-- `ctx.tools.execute(exec)` losslessly snapshots and freezes arguments, assigns an opaque token, runs the complete policy/dispatch/result pipeline, then independently snapshots the authoritative outcome before final observation. Invalid arguments use the same result path without reaching policy or the body; around wrappers may replace only `signal`.
+- `ctx.tools.execute(exec)` losslessly snapshots and freezes arguments, assigns an opaque token, runs the complete policy/dispatch/result pipeline, then independently snapshots the authoritative outcome before final observation. Invalid arguments use the same result path without reaching policy or the body. Around wrappers may replace only `signal`; the registry re-fuses the original caller signal immediately before the body.
 - `ctx.tools.executionMode(exec)` returns `parallel` only when the visible definition's `isConcurrencySafe(exec.arguments)` classifier returns exactly `true`; unknown, hidden, undeclared, invalid, or throwing classifications are exclusive.
 
 ### Injected services
 
 `SystemPrompt` — the registry automatically feeds its tool schemas into the system-prompt assembly via `ctx.systemPrompt.tools()`. The approval seam is consumed opportunistically instead (`ctx.get('approval')`, no static inject): a deployment without it keeps the ask→deny degrade, and the registry stays active either way.
 
+### Cancellation
+
+Cancellation is cooperative and quiescent. Every typed invocation supplies a caller-owned `AbortSignal`; tool bodies receive it as required readonly `exec.signal`, while only `tools/execute` wrappers may temporarily replace the required signal. The registry preserves caller cancellation through replacement and never races away from a started same-process promise. Cancellation before body invocation is `ABORTED_BEFORE_DISPATCH`; cancellation after invocation can replace only a successful outcome with `ABORTED`. A denial, wrapper failure, tool failure, post-policy failure, or timeout-owned `TOOL_TIMEOUT` remains more specific. A pre-aborted entry materializes and freezes arguments, then skips every policy and dispatch phase and publishes one result. Every async tool must observe or forward the signal and settle only after owned work stops. The [tool-cancellation Agent Note](../../../.agents/notes/implemented/architecture/2026-07-19-cooperative-tool-cancellation.md) owns the full contract and hard-termination limit.
+
 ### Live events
 
 The live registry pipeline has three transformable waterfalls followed by the observe-only `tools/result` boundary; registry changes are deliberately unfiltered shared-state notifications. Exact signatures, dispatch modes, scope filtering, and failure-containment contracts live in the generated [Cordis event catalog](../../../docs/cordis-catalog/events.md), while the complete ordering is visualized in the generated [tool execution pipeline](../../../docs/tool-execution-pipeline.md). `tools/result` is live; the similarly named `tool/result` is the durable session event the agent loop appends afterwards.
 
 ### Key types
 
-- `ToolDefinition` — `ToolSchema` + mandatory `output { schema, render, presentationMeta? }` + `execute(args, exec)`, optional presentation callbacks, cooperative `timeoutMs`, and optional per-call `isConcurrencySafe(args)` classification. A body returns only the canonical JSON value declared by the output schema.
-- `ToolExecutionInput` — the caller-supplied call description: `{ callId, name, arguments, agent?, parent?, signal? }`; callers may pass an enclosing execution's opaque token as `parent` but never choose the new execution's own token.
+- `ToolDefinition` — `ToolSchema` + mandatory `output { schema, render, presentationMeta? }` + `execute(args, exec)`, optional presentation callbacks, cooperative `timeoutMs`, and optional per-call `isConcurrencySafe(args)` classification. A body returns only the canonical JSON value declared by the output schema and cooperatively stops through `exec.signal`.
+- `ToolExecutionInput` — the caller-supplied call description: `{ callId, name, arguments, signal, agent?, parent? }`; `signal` is required and readonly, callers may pass an enclosing execution's opaque token as `parent`, and callers never choose the new execution's own token.
 - `ToolExecutionToken` — a fresh branded `Symbol` assigned by the registry. It supports equality correlation only and never crosses a model, log, or worker boundary.
-- `ToolExecution` — the pipeline-owned call: immutable `{ token, callId, name, arguments, agent?, parent? }` identity plus optional operational `signal`, which an around wrapper may add, replace, remove, and restore. A nested call's `parent` is a `ToolExecutionToken`, not an execution object.
-- `ToolRunContext` — the execution passed to a tool body, extending `ToolExecution` with `deferContext(context)`. Composite tools use it to ferry context produced by nested dispatches to the outer result even when the tool later throws; it never injects immediately.
+- `ToolExecution` — the readonly pipeline view: immutable `{ token, callId, name, arguments, signal, agent?, parent? }`; the registry separately retains and re-fuses the original caller signal. `ToolDispatchExecution` is the `tools/execute`-only view whose required signal is mutable, so a wrapper may replace and restore it but cannot delete it. A nested call's `parent` is a `ToolExecutionToken`, not an execution object.
+- `ToolRunContext` — the execution passed to a tool body, extending `ToolExecution` with `deferContext(context)`. Composite tools use it to ferry context produced by nested dispatches to the outer result even when the tool later throws or cancellation wins; it never injects immediately.
 - `ToolExecutionResult` — discriminated execution-local outcome. Success is `{ isError:false, value:JsonValue, content, meta?, additionalContexts? }`; failure is `{ isError:true, error:{ message, info? }, content, meta?, additionalContexts? }` and has no value. Call identity stays on the immutable `ToolExecution`. The registry snapshots, validates, and freezes the canonical value before rendering, then materializes the durable presentation fields before final observation. `ToolFailure.info` carries an internal `{ name, code }` for a `HarnessError`; `additionalContexts` preserves every deferred or post-execute `HookContext` for the loop's post-result FIFO.
 - `PreToolDecision` — `{kind:'allow'}` | `{kind:'deny', reason}` | `{kind:'ask', reason?}`. Input rewrite is deliberately not offered; `ask` is serviced by [`ctx.approval`](../../ui/user-approval/README.md) when mounted and otherwise degrades to deny.
 - `PostToolDecision` — accept may replace `content` or `value`, never both, and may attach `additionalContexts`; block turns feedback into a valueless failure. Content replacement preserves the canonical value and metadata. Value replacement is revalidated and rerenders content/metadata. Accept preserves tool-deferred contexts before decision contexts; block discards tool-deferred contexts and exposes only contexts explicitly supplied by the blocking decision.
@@ -78,7 +82,7 @@ ctx.tools.register(defineTool({
   },
   async execute(args, exec) {
     // args is typed: { path: string; offset?: number; limit?: number }
-    return readFile(args.path, 'utf8')
+    return readFile(args.path, { encoding: 'utf8', signal: exec.signal })
   },
 }))
 ```