Merge branch 'codex/simp-unify-agent-session-id' into codex/simp-ui-identity-residue

# Conflicts:
#	docs/event-producer-consumer.md

docs/architecture.md

@@ -56,7 +56,7 @@ Default loop processing remains exposed through plugin-visible services and even
 
 A **session** is an append-only event log. A **turn** drains queued input until the model stops asking for tools and no plugin requests continuation. A **step** is one model request plus the tool executions caused by that response. In the flow below ([sequence companion](agent-lifecycle.md)), quoted names are durable session events and event names are extension points.
 
-Startup resolves one identity. No id mints `<config-id>-session-<uuid>`; `sessionId` resumes stored or creates; `resumeSessionId` requires history. Failures emit `agent-loop/config-start-failed(sessionId, error)`, so front doors reject buffered work.
+Startup resolves identity. No id mints `<config-id>-session-<uuid>`; `sessionId` resumes or creates; `resumeSessionId` requires history. Active failures emit `agent-loop/config-start-failed(sessionId, error)`, so front doors reject work; teardown stays silent.
 
 ### Turn Flow
 

docs/config-catalog.md

@@ -131,7 +131,7 @@ export interface Config {
 
 Depends on: [`AgentOptions`](../packages/core/agent/src/index.ts) · [`SessionId`](../packages/core/session/src/index.ts)
 
-Source: [`packages/core/agent-loop/src/index.ts:353`](../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:354`](../packages/core/agent-loop/src/index.ts)
 
 ## `@deepseek-ai/dsh-bash-local`
 

docs/cordis-catalog/events.md

@@ -179,13 +179,13 @@ Source: [`packages/core/agent/src/types.ts:576`](../../packages/core/agent/src/t
 
 ### `agent-loop/config-start-failed` — emit
 
-A declarative agent entry failed before it could publish a live agent. Consumers that buffer work for the configured identity use this transient signal to reject that work instead of waiting forever.
+A declarative agent entry failed before it could publish a live agent. Consumers that buffer work for the configured identity use this transient signal to reject that work instead of waiting forever. Normal factory teardown suppresses failures from the cancelled startup attempt.
 
 ```ts cordis-catalog
 'agent-loop/config-start-failed'(sessionId: SessionId, error: unknown): void
 ```
 
-Source: [`packages/core/agent-loop/src/index.ts:348`](../../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:349`](../../packages/core/agent-loop/src/index.ts)
 
 ## `approval/*`
 

docs/cordis-catalog/services.md

@@ -19,7 +19,7 @@ async createAgent(ownerCtx: Context, options: CreateAgentOptions): Promise<Agent
 async resume(ownerCtx: Context, options: ResumeAgentOptions): Promise<AgentHandle>
 ```
 
-Source: [`packages/core/agent-loop/src/index.ts:368`](../../packages/core/agent-loop/src/index.ts)
+Source: [`packages/core/agent-loop/src/index.ts:369`](../../packages/core/agent-loop/src/index.ts)
 
 ## `ctx.agents` — `AgentRegistry`
 
@@ -247,7 +247,7 @@ list(): Session[]
 fork(source: SessionForkSource, boundary?: number, childSessionId?: SessionId): Session
 ```
 
-Source: [`packages/core/session/src/index.ts:598`](../../packages/core/session/src/index.ts)
+Source: [`packages/core/session/src/index.ts:609`](../../packages/core/session/src/index.ts)
 
 ## `ctx.skills` — `SkillService`
 

docs/core-data-structures/session.md

@@ -109,7 +109,7 @@ export interface EpochHeader {
 }
 ```
 
-Canonical form: an empty system prompt, an empty tool list, and an empty session prefix are absent fields, matching how requests are built. `messagePrefix` is the durable record of the `agent/session-prefix` waterfall's product (the request is `messagePrefix + derived history`); it is composed once per loop instance and included in every full snapshot that instance records. Legacy v0 logs containing the removed `request/header-delta` format are rejected at seed and persistence-load boundaries rather than replayed incompletely.
+Canonical form: an empty system prompt, an empty tool list, and an empty session prefix are absent fields, matching how requests are built. `messagePrefix` is the durable record of the `agent/session-prefix` waterfall's product (the request is `messagePrefix + derived history`); it is composed once per loop instance and included in every full snapshot that instance records. Legacy v0 logs containing the removed `request/header-delta` event or its full-snapshot `fallback` reason are rejected at seed, append, and persistence-load boundaries rather than replayed incompletely.
 
 ## `SessionEvent<T>` — one log entry
 

docs/event-producer-consumer.md

@@ -7,7 +7,7 @@ This matrix shows which packages dispatch each harness-owned event and which pac
 
 | Event | Mode | Declared in | Dispatchers | Listeners |
 | --- | --- | --- | --- | --- |
-| `agent-loop/config-start-failed` | `emit` | [`packages/core/agent-loop/src/index.ts:348`](../packages/core/agent-loop/src/index.ts) | [`agent-loop`](../packages/core/agent-loop) (`events.dispatch`) | [`stdio-agent`](../packages/ui/stdio-agent) |
+| `agent-loop/config-start-failed` | `emit` | [`packages/core/agent-loop/src/index.ts:349`](../packages/core/agent-loop/src/index.ts) | [`agent-loop`](../packages/core/agent-loop) (`events.dispatch`) | [`stdio-agent`](../packages/ui/stdio-agent) |
 | `agent/created` | `emit` | [`packages/core/agent/src/types.ts:304`](../packages/core/agent/src/types.ts) | [`agent`](../packages/core/agent) (`events.dispatch`) | [`stdio-agent`](../packages/ui/stdio-agent) |
 | `agent/disposed` | `emit` | [`packages/core/agent/src/types.ts:319`](../packages/core/agent/src/types.ts) | [`agent`](../packages/core/agent) (`events.dispatch`) | [`stdio-agent`](../packages/ui/stdio-agent) |
 | `agent/error` | `emit` | [`packages/core/agent/src/types.ts:593`](../packages/core/agent/src/types.ts) | [`agent-loop`](../packages/core/agent-loop) (`emit`) | - |

docs/rfc/implemented/simplification/2026-07-12-simplify-session-log-representation.md

@@ -18,7 +18,7 @@ This proposal deliberately retains append and replacement `sourceEventSeqs`, cra
 
 Request headers use canonical full snapshots only. Initial and resume anchors remain full snapshots even when unchanged; an in-instance change appends another full `request/header` with reason `change`. The delta event, codec types, diff/apply helpers, and codec-only `fallback` reason are removed. Request reconstruction selects the latest snapshot.
 
-`SESSION_FORMAT_VERSION` remains pinned at `0`, so seed and persistence-load validation explicitly reject an old v0 log containing `request/header-delta`. There is no compatibility fold or migration. JSONL and SQLite tests pin this fail-loud boundary, and the ACP snapshot harness represents legitimate mid-session changes as full pinned headers and full readable prompts.
+`SESSION_FORMAT_VERSION` remains pinned at `0`, so seed, append, and persistence-load validation explicitly reject old v0 `request/header-delta` events and full snapshots carrying the removed `fallback` reason. There is no compatibility fold or migration. JSONL and SQLite tests pin this fail-loud boundary, and the ACP snapshot harness represents legitimate mid-session changes as full pinned headers and full readable prompts.
 
 ## Alternatives considered