Merge remote-tracking branch 'origin/worktree-hooks-b-bash-seam' into worktree-hooks-c-interception

# Conflicts:
#	docs/architecture.md
#	packages/core/agent-loop/README.md

docs/architecture.md

@@ -24,6 +24,7 @@ For a catalog of the **data structures** this architecture moves around — the
 │  @deepseek-ai/dsh-agent-loop      (the ONE concrete plugin)  │
 │  @deepseek-ai/dsh-bash-local      (bash impl)                │
 │  @deepseek-ai/dsh-tool-bash       (bash tool schemas)        │
+│  @deepseek-ai/dsh-subagent-*      (subagent providers)       │
 │  @deepseek-ai/dsh-session-persistence-jsonl (persistence impl)│
 ├─────────────────────────────────────────────────────────────┤
 │  @deepseek-ai/dsh-agent           (vocabulary + registry)    │
@@ -33,6 +34,8 @@ For a catalog of the **data structures** this architecture moves around — the
 │  @deepseek-ai/dsh-session-persistence (persistence seam)     │
 │  @deepseek-ai/dsh-llm             (abstract model service)   │
 │  @deepseek-ai/dsh-bash            (abstract bash executor)   │
+│  @deepseek-ai/dsh-compact         (abstract compaction seam) │
+│  @deepseek-ai/dsh-subagent        (provider registry seam)   │
 ├─────────────────────────────────────────────────────────────┤
 │  vendor/: cordis, loader, include, group, timer, hmr,        │
 │           logger-console, cosmokit, schemastery              │
@@ -54,6 +57,7 @@ Dependency rule: **extension** plugins depend on interface packages, never on `d
 | `ctx.agentLoop` | `AgentLoop` | dsh-agent-loop | creates `ReactLoopAgent`s and drives their loops |
 | `ctx.bash` | `BashExecutor` (abstract) | dsh-bash | bash execution seam: foreground runs + background tasks |
 | `ctx.compact` | `CompactService` (abstract) | dsh-compact | compaction seam: decide when history is too large, summarize an older range into a single surface node |
+| `ctx.subagents` | `SubagentService` | dsh-subagent | named provider registry for delegating a task to child agents |
 
 All registrations (`registerAdapter`, `section`, `tools`, `register`, …) go through `ctx.effect()` and return disposers, so plugin hot-reload (vendored HMR) and fiber disposal clean up automatically.
 
@@ -86,11 +90,11 @@ A `Session` is an append-only log of typed `SessionEvent`s — the single source
 - `user/message` → user message
 - `assistant/message` → assistant message (raw `assistant/chunk` events are replay/UI data and are skipped in derivation; an empty-content `assistant/message`, which exists only to host a max-tokens step's `usage`, is skipped too)
 - `tool/result` → user message carrying a `tool-result` block
-- `context/message`, `steering/message` → user-role messages wrapped in a tagged envelope (`<context source="…">…</context>`) at their chronological position — the "system-reminder" pattern; models distinguish them from real user prompts by the envelope. **TODO(review)**: the real adapters now exist (the original precondition); the envelope still wants a deliberate review against live model behavior (`TODO(review)` in dsh-session).
+- `context/message`, `steering/message` → user-role messages wrapped in a tagged envelope (`<context source="…">…</context>`) at their chronological position — the "system-reminder" pattern; models distinguish them from real user prompts by the envelope. Live-adapter review has validated the tagged-envelope rendering against current DeepSeek behavior; provider-specific mismatches belong in that adapter.
 
 Replay/fork = `ctx.sessions.create(id, { seed: seedEvents })`. Trace/telemetry = listen to `session/event`.
 
-**Durability seam**: `session/event` is a synchronous notification; persistence plugins buffer (write-behind) and drain at the awaited `session/flush` checkpoint the loop fires at every turn end. The durable backend is a real **capability seam**: the abstract `SessionPersistence` service (`dsh-session-persistence`, `ctx.sessionPersistence`) defines create/append/load/list over the existing `SessionEvent` (no parallel persisted type), and `dsh-session-persistence-jsonl` is the first implementation — an append-only JSONL log per session with crash-safe atomic writes, crash recovery that PRESERVES an interrupted turn (closing it with a synthetic `turn/end {interrupted}` rather than truncating — a turn can be huge), and a read/replay path. Session metadata (format version, cwd, lineage) travels separately as `SessionHeader`, attached to a `Session` via `session.header`. Resuming a persisted session into a live agent is `ctx.agents.resume({ resumeSessionId })`. A second backend, `dsh-session-persistence-sqlite` (`node:sqlite`, one row per `SessionEvent` — the row shape `(session_id, seq, type, time, data)` maps 1:1 onto it), passes the same `runPersistenceContract` suite, proving the seam is genuinely backend-agnostic.
+**Durability seam**: `session/event` is a synchronous notification; persistence plugins buffer (write-behind) and drain at the awaited `session/flush` checkpoint the loop fires at every turn end. The durable backend is a real **capability seam**: the abstract `SessionPersistence` service (`dsh-session-persistence`, `ctx.sessionPersistence`) defines create/append/load/list over the existing `SessionEvent` (no parallel persisted type), and `dsh-session-persistence-jsonl` is the first implementation — an append-only JSONL log per session with crash-safe atomic writes, crash recovery that PRESERVES an interrupted turn (closing it with a synthetic `turn/end {interrupted}` rather than truncating — a turn can be huge), and a read/replay path. Session metadata (format version, cwd, lineage, seed boundary) travels separately as `SessionHeader`, attached to a `Session` via `session.header`. Resuming a persisted session into a live agent is `ctx.agents.resume({ resumeSessionId })`. A second backend, `dsh-session-persistence-sqlite` (`node:sqlite`, one row per `SessionEvent` — the row shape `(session_id, seq, type, time, data, source_event_seqs, surface_op)` maps 1:1 onto it), passes the same `runPersistenceContract` suite, proving the seam is genuinely backend-agnostic.
 
 ## Prompt assembly (dsh-system-prompt)
 
@@ -212,7 +216,7 @@ Every MVP feature (including the TODO-marked ones), with the mechanism that impl
 | Tool sandbox (landlock / sandbox-exec) | `tools/pre-execute` (deny), or implement a sandboxing `BashExecutor` (the dsh-bash seam) |
 | Permission system / AskUserQuestion | `tools/pre-execute` (deny/ask); register an ask tool |
 | Plan mode | `tools/pre-execute` (deny writes) + `agent/request` (inject mode prompt) |
-| Sub-agents (spawn / fork / steer) | TODO seam on `AgentLoop.create()`; fork = seed Session with parent events; `steer()` on the child handle |
+| Sub-agent delegation | Implemented as the `ctx.subagents` provider-registry seam: `dsh-subagent-spawn` starts a fresh in-process child, `dsh-subagent-fork` seeds a child from the parent's completed-turn prefix, `dsh-subagent-acp` drives an out-of-process child over ACP, and `dsh-tool-subagent` exposes one configured provider to the model |
 | MCP | one plugin per server: discover tools → `ctx.tools.register()` |
 | Skills | section + tool registration; `inject()` skill content on invocation |
 | Memory | section provider + tool |
@@ -230,7 +234,7 @@ Code skeletons for the three plugin shapes (tool, hook/permission-gate, UI) and
 
 Tracked here deliberately — each is designed-for but not implemented:
 
-- **Sub-agent spawn/fork semantics** (seam: `AgentLoop.create()`); inter-agent channels beyond `send`/`steer`/events.
+- **Inter-agent channels beyond delegation** (shared state, streaming child output, background/poll semantics) remain out of scope for the current `ctx.subagents` seam.
 - **Compaction implementation** (auto thresholds, summarization prompts) on the `agent/request` seam, with its session-event types added by declaration merging.
 - **Parallel tool execution** (concurrency-safety hints on ToolDefinition).
 - **Session branching/tree** (pi-style entry tree) if needed beyond seed-based forking.

docs/core-data-structures/persistence.md

@@ -14,7 +14,7 @@ A backend that reloads a log crashed mid-turn finds an open `turn/start` with no
 
 ## `SessionHeader` — metadata beside the log
 
-Per-session metadata travels **separately** from the event log: format version, cwd, and lineage are storage concerns, not conversation events, so they stay out of `SessionEventMap` and never reach `deriveMessages()`. The header is attached to a `Session` via `session.header`.
+Per-session metadata travels **separately** from the event log: format version, cwd, lineage, and the seed boundary are storage concerns, not conversation events, so they stay out of `SessionEventMap` and never reach `deriveMessages()`. The header is attached to a `Session` via `session.header`.
 
 Source: [`packages/core/session/src/types.ts`](../../packages/core/session/src/types.ts)
 
@@ -78,6 +78,6 @@ Replay/fork is therefore `ctx.sessions.create(id, { seed: seedEvents })`; resumi
 Both implement the same abstract `SessionPersistence` (create/append/load/list over `SessionEvent`) and pass `runPersistenceContract`, proving the seam is genuinely backend-agnostic:
 
 - **[dsh-session-persistence-jsonl](../../packages/session-persistence/session-persistence-jsonl)** — an append-only JSONL log per session with crash-safe atomic writes, the interrupted-turn crash recovery above, and a read/replay path.
-- **[dsh-session-persistence-sqlite](../../packages/session-persistence/session-persistence-sqlite)** — `node:sqlite`, one row per `SessionEvent`. The row shape `(session_id, seq, type, time, data)` maps 1:1 onto the event, so there is no parallel persisted schema to keep in sync.
+- **[dsh-session-persistence-sqlite](../../packages/session-persistence/session-persistence-sqlite)** — `node:sqlite`, one row per `SessionEvent`. The row shape `(session_id, seq, type, time, data, source_event_seqs, surface_op)` maps 1:1 onto the event, including optional surface metadata, so there is no parallel persisted schema to keep in sync.
 
 Multiple backends sharing one on-disk session coordinate writes through the [shared persistence write-coordinator](../rfc/implemented/architecture/2026-06-18-shared-persistence-write-coordinator.md).

docs/development.md

@@ -61,7 +61,7 @@ lefthook is configured in `lefthook.yml` as an early local checkpoint before rev
 
 The vendor manifest guard checks that changes under `vendor/*/src` are staged with the matching `vendor/README.md` manifest update. See `vendor/README.md` before editing vendored code.
 
-These hooks do not exactly mirror CI. Notably, `pre-push` runs unit tests without coverage, while CI runs `pnpm run test:coverage`; CI also runs an echo-agent smoke test and exercises the matrix on Node 24 and 26.
+These hooks do not exactly mirror CI. Notably, `pre-push` runs unit tests without coverage, while CI runs `pnpm run test:coverage`; CI also runs echo-agent and built-bin smoke tests and exercises the matrix on Node 24 and 26.
 
 ## CI gates
 
@@ -78,6 +78,7 @@ The GitHub workflow runs these gates on each pull request:
 - `pnpm run build`
 - `pnpm run hygiene`
 - an echo-agent smoke test that checks the demo's tool call, tool result, and JSONL output
+- built-bin smoke tests that run the published `lib/bin.js` entrypoints under plain `node`
 
 `pnpm run hygiene` is the local shorthand for `pnpm run knip && pnpm run publint && pnpm run constraints && pnpm run verify-node-next-types`; CI also runs `pnpm run constraints` as an earlier fail-fast step, then runs the full hygiene script after `pnpm run build`.
 
@@ -121,6 +122,12 @@ The coding-agent demo uses the real DeepSeek adapter and needs `DEEPSEEK_API_KEY
 pnpm run demo:coding
 ```
 
+The ACP server demo exposes the same coding agent over JSON-RPC stdio and also needs `DEEPSEEK_API_KEY`:
+
+```sh
+pnpm run demo:acp
+```
+
 ## TODO markers
 
 Use one of three comment tags to flag known issues in the code, ordered by urgency:

docs/rfc/implemented/architecture/2026-06-30-bash-stdin-env-trusted-plugin-surface.md

@@ -6,7 +6,7 @@ Status: implemented (accepted 2026-06-30)
 
 ## Context
 
-The hooks subsystem (stack PR-A…PR-F) runs external hook commands the way Claude Code and Codex do: a hook is a shell command that receives its event payload as **JSON on stdin** and reads context from a handful of **environment variables** (`CLAUDE_PROJECT_DIR`, `CLAUDE_PLUGIN_ROOT`, `PLUGIN_ROOT`, …). The harness already has a perfectly good command runner behind the `ctx.bash` capability seam ([dsh-bash](../../../../packages/bash/bash) → [dsh-bash-local](../../../../packages/bash/bash-local)), with process-group kills, output truncation/spill, and a credential scrub. Reusing it for hook execution means the bridges do not re-implement subprocess plumbing — but the seam had no way to write stdin or set extra env.
+The hooks subsystem runs external hook commands the way Claude Code and Codex do: a hook is a shell command that receives its event payload as **JSON on stdin** and reads context from a handful of **environment variables** (`CLAUDE_PROJECT_DIR`, `CLAUDE_PLUGIN_ROOT`, `PLUGIN_ROOT`, …). The harness already has a perfectly good command runner behind the `ctx.bash` capability seam ([dsh-bash](../../../../packages/bash/bash) → [dsh-bash-local](../../../../packages/bash/bash-local)), with process-group kills, output truncation/spill, and a credential scrub. Reusing it for hook execution means a hook bridge does not re-implement subprocess plumbing — but the seam had no way to write stdin or set extra env.
 
 The friction is that those two inputs are **dangerous in exactly the way the seam was built to prevent**. [dsh-bash-local](../../../../packages/bash/bash-local)'s `childEnv()` deliberately scrubs `*KEY*`/`*SECRET*`/`*TOKEN*` from the child environment so the harness's own `DEEPSEEK_API_KEY` cannot leak into model-driven command output (see [AGENTS.md](../../../../AGENTS.md) § Defensive patterns, "Never hand untrusted/model output the ambient environment or predictable paths"). An arbitrary-env / arbitrary-stdin capability is the opposite of that guarantee. So the question this RFC answers is not "can we add stdin/env" — it is "who is allowed to use them, and how is that boundary enforced".
 
@@ -30,4 +30,4 @@ An earlier sketch of this work also proposed making `SENSITIVE_ENV_PATTERN` conf
 
 ## Consequences
 
-The hooks bridges (PR-F) build a `BashExecRequest` with the hook's JSON payload as `stdin` and its `CLAUDE_*`/`PLUGIN_ROOT` vars as `env`, and run it through the same `ctx.bash` everything else uses — no bespoke subprocess code, and the full process-group-kill / truncation / spill machinery for free. The model-facing attack surface is unchanged: the consumer's request-building is the single boundary, guarded by a test that fails if it regresses. The vocabulary addition is documented in [docs/core-data-structures/bash.md](../../../core-data-structures/bash.md) (the `type-equiv` request/spec blocks) and the three bash-package READMEs; the trusted-plugin rule mirrors the existing scrub/predictable-path discipline in [AGENTS.md](../../../../AGENTS.md) § Defensive patterns.
+A hook bridge builds a `BashExecRequest` with the hook's JSON payload as `stdin` and its `CLAUDE_*`/`PLUGIN_ROOT` vars as `env`, and runs it through the same `ctx.bash` everything else uses — no bespoke subprocess code, and the full process-group-kill / truncation / spill machinery for free. The model-facing attack surface is unchanged: the consumer's request-building is the single boundary, guarded by a test that fails if it regresses. The vocabulary addition is documented in [docs/core-data-structures/bash.md](../../../core-data-structures/bash.md) (the `type-equiv` request/spec blocks) and the three bash-package READMEs; the trusted-plugin rule mirrors the existing scrub/predictable-path discipline in [AGENTS.md](../../../../AGENTS.md) § Defensive patterns.