docs(core): update session start source event reference

docs/subsystems/core.i18n.yaml

@@ -2,5 +2,5 @@
 # side as of the last confirmed-consistent state. Both languages carry equal authority;
 # after editing either side, bring the other along and re-record with:
 #   pnpm run verify-translation-pairing --write docs/subsystems/core.md
-core.md: b903c4fe7908470a2800cd83c704640548792b7a
-core.zh.md: efd166138435fd66a6a82fbc817b6b70dff70911
+core.md: 51a4f11e1d49c6804e2b8b7251c5559484f625de
+core.zh.md: 1715e3023d87969d084bba2e79674a9f9be3fca1

docs/subsystems/core.md

@@ -336,7 +336,7 @@ type RequestErrorAction = { kind: 'retry' } | undefined
 
 `agent/pre-step` is the only waterfall listener chain before request derivation. `agent/turn-stopping` runs when a turn has no tool or steering continuation, before one final steering drain.
 
-`agent/session-start` carries a `SessionStartSource` (why the session lifecycle began; a bridge keys its SessionStart matcher on it):
+`agent/created` carries a `SessionStartSource` (why the session lifecycle began; a bridge keys its SessionStart matcher on it):
 
 ```ts type-equiv
 /** Why a session lifecycle began; seeded creates are `startup`, while persisted loads are `resume`. */

docs/subsystems/core.zh.md

@@ -344,7 +344,7 @@ type RequestErrorAction = { kind: 'retry' } | undefined
 
 `agent/pre-step` 是请求推导前唯一的 waterfall（瀑布式）监听器链。`agent/turn-stopping` 在轮次没有工具或 steering（中途引导）后续时运行，先于最后一次 steering 排空。
 
-`agent/session-start` 携带 `SessionStartSource`（会话生命周期为何开始；桥接层据此匹配其 SessionStart）：
+`agent/created` 携带 `SessionStartSource`（会话生命周期为何开始；桥接层据此匹配其 SessionStart）：
 
 ```ts type-equiv
 /** Why a session lifecycle began; seeded creates are `startup`, while persisted loads are `resume`. */