Merge remote-tracking branch 'origin/master' into codex/trim-ai-prose

# Conflicts:
#	docs/config-catalog.md
#	docs/event-producer-consumer.md
#	docs/rfc/implemented/feature/2026-07-05-dynamic-workflows.md
#	examples/acp-agent/tests/acp.snapshot.ts
#	packages/code-runtime/code-runtime-worker/tests/built-lib.e2e.ts
#	packages/code-runtime/code-runtime-worker/tsdown.config.ts

docs/rfc/implemented/feature/2026-07-05-dynamic-workflows.md

@@ -26,7 +26,9 @@ One deliberate strictness DIVERGENCE from CC: hook misuse — unknown or deferre
 
 **Why `node:worker_threads`**: each run gets one unpooled worker. A vm context limits the documented script surface, while message-port RPC bridges `agent()` to host-side child loops. The worker prevents synchronous script work from blocking the host, provides a serialization boundary, and permits forced termination after cancellation. `isolated-vm` was rejected because of its maintenance state and deployment requirements.
 
-The host validates metadata and parses the body before publication. Private enum-keyed payload maps define the wire protocol, and host-owned records preserve the subagent run contract across it. The [agent-scope runtime-design RFC](../architecture/2026-07-12-agent-scope-runtime-design.md#workflow-children-are-pending-starts-or-published-records) owns the start, cancellation, worker-death, result-precedence, and disposal algorithms.
+The host validates metadata and parses the body before publication. Private enum-keyed payload maps define the wire protocol; pending starts, published child records, one cancellation signal, worker-death reaping, result precedence, and disposal quiescence preserve the subagent run contract across it. The [agent-scope runtime-design RFC](../architecture/2026-07-12-agent-scope-runtime-design.md#workflow-children-are-pending-starts-or-published-records) owns those race algorithms.
+
+Coverage uses an in-process `MessageChannel` for worker-side logic that main-process V8 coverage cannot see. The built-bin gate separately runs the `"./worker"` export's `lib/worker.cjs` entry under plain Node.
 
 **Meta is data**: the schema-validated `meta` field reaches the seam as JSON and is only shape-validated. The host never evaluates a metadata literal, which would let script-controlled accessors run outside the worker's isolation.
 
@@ -46,7 +48,7 @@ An output schema makes a schema-valid committed capture mandatory for successful
 
 ## Testing
 
-Worker-side logic runs through an in-process `MessageChannel` so V8 coverage measures it. Unit tests cover script helpers, fatal and nullable failures, JSON boundaries, caps, cancellation, child ownership, and structured output through real loops. A built-lib smoke runs the separately bundled `lib/worker.js` under plain Node, a with-key e2e drives real child agents, and model-facing workflow behavior is snapshot-covered through its owning example.
+Worker-side logic runs through an in-process `MessageChannel` so V8 coverage measures it. Unit tests cover script helpers, fatal and nullable failures, JSON boundaries, caps, cancellation, child ownership, and structured output through real loops. A built-lib smoke runs the separately bundled `lib/worker.cjs` under plain Node, a with-key e2e drives real child agents, and model-facing workflow behavior is snapshot-covered through its owning example.
 
 ## Deferred (documented non-goals of this cut)
 

docs/rfc/implemented/feature/2026-07-07-session-prefix.md

@@ -20,6 +20,10 @@ Three properties carry the design:
 
 Because composition runs before the boundary snapshot, a composing listener's session append joins the CURRENT request's derived history. Compaction structurally cannot touch the prefix (or the system prompt): it rewrites surface nodes, and header state never enters the surface.
 
+## Testing
+
+[Interception tests](../../../../packages/core/agent-loop/tests/interception.spec.ts) pin compose-once reuse with no header deltas, prepend order, empty-prefix omission, immutability, and composition before pre-step; [cancellation tests](../../../../packages/core/agent-loop/tests/cancel.spec.ts) pin discard and recomposition. Session codec, invariant, and compaction tests cover header round trips, request reconstruction, and prefix-aware pressure accounting. Snapshot normalization preserves prefix counts, while the [pinned-header scenario](../testing/2026-07-06-pin-request-header-content-in-one-scenario.md) owns content and the default example remains prefix-free. No prefix-specific e2e is needed because the seam is deterministic and provider-independent; the with-key [request-cache e2e](../../../../packages/core/agent-loop/tests/request-cache.e2e.ts) covers its cache economics.
+
 ## Alternatives considered
 
 - **Per-request `before`/`after` slots recomputed every step** (the shape first proposed: a waterfall firing on every request, contributing frozen `before` messages ahead of the history and fresh `after` messages behind it) — rejected. A per-step `before` recompose invites silent drift — nothing anchors it to the log short of logging a header delta per step — and an `after` slot sits behind the growing history, so its tokens re-pay on every request and everything after it is uncacheable. Measured against the alternatives, every current update pattern is served cheaper by a durable append (paid once, cache-read thereafter), and the only content with no home was the session-stable opener — which wants freezing, not recomputation.