fix(agent): route loop dispatches through prebuilt fused dispatcher

Address review feedback on PR #1738:
- ReactLoopAgent builds its AgentEventDispatch once in the constructor and
  routes every emit/serial/waterfall through it, so hot-path dispatches no
  longer allocate a carrier and dispatcher per call; the public carrier
  field is gone (fused dispatcher is private).
- agentEvents accepts an optional prebuilt carrier.
- The fused payload builder spreads the payload before the injected agent
  so a structurally acceptable payload carrying an agent field can never
  override the subject.
- Regenerate doc graphs; re-record core + architecture + affected Agent
  Note translation pairs; add payload-object event contract Agent Note.
This commit is contained in:
_Kerman
2026-08-06 13:44:23 +08:00
parent 23671848c3
commit 262d044642
23 changed files with 143 additions and 61 deletions
@@ -15,8 +15,8 @@ The surface needs distinct contracts for per-prompt policy (CC's `UserPromptSubm
The canonical surface separates transformable policy, around-dispatch control, and observe-only notification. Policy waterfalls return small seam-specific **typed Decision unions**; wrappers return normalized results; notifications receive immutable snapshots and cannot affect the outcome. The set covers the hook points in scope (`session-start`, `prompt-submit`, `pre-tool`, `post-tool`, `stop`-via-continuation) while leaving non-hook execution policy independently composable.
**Agent events** (`dsh-agent`):
- `agent/session-start(agent, source)` — emit, once before turn 1, carrying a `SessionStartSource` (`startup` for a fresh/forked create, `resume` for a reloaded persisted session; `clear`/`compact` reserved). A pure notification — it CANNOT block startup (a deliberate gap: a bridge logs/injects, it does not gate startup). A listener seeds context via `agent.inject()`.
- `agent/pre-step(agent, messages, context, next) → PreStepDecision` — waterfall, fired before every proposed step after the loop has atomically removed its exclusive inbox batch. `PreStepContext` carries that request's `turn`, `step`, and cancellation `signal`; `messages` is empty for a tool continuation with no intervening input. `enter` returns the complete message batch, including any current-request context a listener contributes; `reject` opens no step and leaves the claimed messages removed.
- `agent/session-start({ agent, source })` — emit, once before turn 1, carrying a `SessionStartSource` (`startup` for a fresh/forked create, `resume` for a reloaded persisted session; `clear`/`compact` reserved). A pure notification — it CANNOT block startup (a deliberate gap: a bridge logs/injects, it does not gate startup). A listener seeds context via `agent.inject()`.
- `agent/pre-step({ agent, messages, turn, step, signal }, next) → PreStepDecision` — waterfall, fired before every proposed step after the loop has atomically removed its exclusive inbox batch. The payload carries the request's `turn`, `step`, and cancellation `signal` (the retired `PreStepContext` fields live in the payload; see the [payload-object events decision](../architecture/2026-08-06-agent-event-payload-objects.md)); `messages` is empty for a tool continuation with no intervening input. `enter` returns the complete message batch, including any current-request context a listener contributes; `reject` opens no step and leaves the claimed messages removed.
**`agent/turn-stopping`** is an awaited notification at the natural stop boundary. A listener that needs another step calls `agent.steer()` with explicitly sourced model-facing content; the loop then re-reads the outbox and either continues or closes the turn.