refactor(agent): return request retry action

packages/core/agent-loop/README.md

@@ -64,7 +64,7 @@ Every provider call that reaches a successful finish appends exactly one `assist
 
 After `agent/request` returns a provider/model call config, the loop asks `ctx.llm.prepareCall()` to validate any adapter-owned reasoning effort and materialize its configured default under the active turn signal. The prepared call retains the exact adapter registration across this asynchronous resolution, `request/header` logging, and terminal dispatch, so HMR cannot mix one adapter's capability result with another adapter's request. The effective config is logged before dispatch, so a listener can change effort between steps without hidden request drift. A route with no registered adapter preserves the proposed config so an `llm/stream` listener can own and short-circuit it; unhandled terminal dispatch still fails with `NO_ADAPTER`. A new loop instance restores the last effort only when its initial provider/model route exactly matches the logged route; a route change discards that opaque model-owned ID and resolves the new model independently.
 
-Plugin failure ends the current turn, not the loop. A model-request failure first closes its step and enters `agent/request-error` with the exact live error, normalized provider facts, and the turn signal. A handling listener calls `agent.retry()`; the loop coalesces repeated calls, closes the failed turn with its error, and opens one numbered retry turn without an intervening idle notification. An unhandled failure is terminal. Other failures close directly. AgentLoop owns one cancellation signal for the current admission or turn. An effective `cancel(cause)` clears pending work unless `keepInbox` is set and cooperatively aborts that signal; idle cancellation is a no-op. Durable `turn/end` records `aborted` for `user` and `parent`, while disposal records `disposed`; undispatched model tool calls receive synthetic `tool/call` and `ABORTED_BEFORE_DISPATCH` result pairs. The cancellation cause changes reporting, not how result context finalized after cancellation is handled. Disposal waits for signal-ignoring work before registry removal. The [explicit-cancellation decision](../../../.agents/notes/implemented/architecture/2026-07-16-explicit-turn-cancellation.md) owns the lifecycle and race contract.
+Plugin failure ends the current turn, not the loop. A model-request failure first closes its step and enters `agent/request-error` with the exact live error, normalized provider facts, and the turn signal. A handling listener returns `{ kind: 'retry' }`; the loop closes the failed turn with its error and opens one numbered retry turn without an intervening idle notification. An unhandled failure is terminal. Other failures close directly. AgentLoop owns one cancellation signal for the current admission or turn. An effective `cancel(cause)` clears pending work unless `keepInbox` is set and cooperatively aborts that signal; idle cancellation is a no-op. Durable `turn/end` records `aborted` for `user` and `parent`, while disposal records `disposed`; undispatched model tool calls receive synthetic `tool/call` and `ABORTED_BEFORE_DISPATCH` result pairs. The cancellation cause changes reporting, not how result context finalized after cancellation is handled. Disposal waits for signal-ignoring work before registry removal. The [explicit-cancellation decision](../../../.agents/notes/implemented/architecture/2026-07-16-explicit-turn-cancellation.md) owns the lifecycle and race contract.
 
 Within a step, exclusive calls form barriers; parallel-safe calls use a bounded rolling pool and are reclassified before start. Only dispatch/body overlaps. Policy, durable results, and result context remain model-ordered. Abort stops new calls, drains started results, and retains their finalized result context without distinguishing the cancellation cause.
 
@@ -73,7 +73,7 @@ Within a step, exclusive calls form barriers; parallel-safe calls use a bounded
 Everything that goes beyond "call the model, run the tools, repeat" belongs to plugins listening on the event taxonomy:
 - Hooks and policy: the relevant `agent/*` checkpoints plus the guarded `tools/pre-execute` → `tools/execute` → `tools/post-execute` → definition-owned `finalizeContent` → `tools/result` pipeline; exact event signatures and modes live in the [generated event catalog](../../../docs/cordis-catalog/events.md)
 - Compaction: pressure on `agent/step`; canonical overflow repair on `agent/request-error`
-- Transient model recovery: `dsh-llm-retry` records and waits its finite backoff on `agent/request-error`, then calls `agent.retry()`
+- Transient model recovery: `dsh-llm-retry` records and waits its finite backoff on `agent/request-error`, then returns a retry action
 - Sandbox, permission, plan mode: `tools/pre-execute` for extensible deny/ask, `tools.guard()` for monotonic owner policy, `tools/post-execute` for result decisions, and `tools/result` for final observation
 - Sub-agents: implemented outside the loop as `ctx.subagents` providers; in-process providers use `ctx.agents.create()` and owned `AgentHandle` teardown, while generic [`ctx.tasks`](../../tasks/tasks/) plus [`dsh-tool-subagent`](../../subagent/tool-subagent/) own background collection.
 - Persistence: eager write-behind from `session/event`; `session/flush` is an explicit observation barrier