refactor(llm): simplify live request telemetry (round 2)

.agents/notes/implemented/architecture/2026-07-28-host-owned-web-session-metrics.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 .agents/notes/implemented/architecture/2026-07-28-host-owned-web-session-metrics.md
-2026-07-28-host-owned-web-session-metrics.md: e37a7635cbdae65162308bf8a3a498b5071a4910
-2026-07-28-host-owned-web-session-metrics.zh.md: fd3e50c8cf8c0336a8cb2cd55f6629419bb8ad23
+2026-07-28-host-owned-web-session-metrics.md: bc66ee72dc278196af8bab65c5e118d8f5cf039c
+2026-07-28-host-owned-web-session-metrics.zh.md: a103a8e24bd806ded6131b94f4c123c8d745513d

.agents/notes/implemented/architecture/2026-07-28-host-owned-web-session-metrics.md

@@ -12,7 +12,7 @@ A Web stats line derived from the currently loaded conversation nodes is window-
 
 The Host owns one session-level metrics projection. It incrementally folds the complete durable event log, keys settled usage by `(turn, step)`, and replaces an earlier usage record for the same key instead of double-counting chunk and message forms. Uncached input, output, cache reads, and cache writes remain four disjoint cumulative buckets. Compaction can change the current prompt surface without erasing historical usage.
 
-Current context pressure is the point-in-time `tokenMeter.measure(session).totalTokens`. Capacity instead belongs to the latest model request observed by the current live mux connection. `LlmService.prepareCall()` retains the context metadata obtained by the exact lookup that also validates reasoning/defaults, and the loop publishes it through one contained `agent/model-request` notification only after the final route has a successfully constructed stream handle. Failed or aborted iteration still counts as a dispatched request; preparation and synchronous construction failures do not.
+Current context pressure is the point-in-time `tokenMeter.measure(session).totalTokens`. Capacity instead belongs to the latest model request attempt observed by the current live mux connection. `LlmService.prepareCall()` retains the context metadata obtained by the exact lookup that also validates reasoning/defaults. After the final provider/model is fixed and the outer `llm/stream` call returns a handle, the loop publishes one contained `agent/model-request` notification. This boundary observes an attempt, not proof of provider I/O: preparation or a synchronous outer waterfall failure emits nothing, while short-circuit handles and later lazy adapter construction, iteration failure, or abort still count.
 
 The tail `session.history` response carries durable usage and pressure, while older pages omit them. Live changes use `session/metrics` mux frames. Both forms carry a durable-log revision and a projection revision; the client accepts only nondecreasing revisions and preserves metrics across older-page prepend.
 

.agents/notes/implemented/architecture/2026-07-28-host-owned-web-session-metrics.zh.md

@@ -12,7 +12,7 @@ Web 统计行若根据当前加载的会话节点推导指标，其结果会随
 
 Host 拥有一项会话级指标投影。它以增量方式归并完整的持久事件日志，按 `(turn, step)` 标识已结算用量；同一标识再次出现时，会替换较早的用量记录，而不会重复统计分片和消息两种形态。未缓存输入、输出、缓存读取与缓存写入保持为四个彼此独立的累计计数项。压缩可以改变当前提示词表层，但不会抹除历史用量。
 
-当前上下文压力是即时的 `tokenMeter.measure(session).totalTokens`。容量则属于当前实时 mux 连接观察到的最新模型请求。`LlmService.prepareCall()` 会保留同一次精确查询取得的上下文元数据，该查询也负责校验推理设置与默认值；仅在最终路由的流句柄成功构造后，循环才会通过一条失败会被收容的 `agent/model-request` 通知发布这些元数据。后续迭代失败或中止仍算作已分派请求；准备阶段失败和同步构造失败则不算。
+当前上下文压力是即时的 `tokenMeter.measure(session).totalTokens`。容量则属于当前实时 mux 连接观察到的最新模型请求尝试。`LlmService.prepareCall()` 会保留同一次精确查询取得的上下文元数据，该查询也负责校验推理设置与默认值。最终提供方／模型确定且外层 `llm/stream` 调用返回句柄后，循环会发布一条失败会被收容的 `agent/model-request` 通知。这个边界观察到的是一次尝试，并不能证明提供方 I/O 已开始：准备阶段或外层 waterfall（瀑布式事件）的同步失败不会发出通知，而短路句柄以及之后的惰性适配器构造、迭代失败或中止仍会计入。
 
 `session.history` 尾页响应携带持久用量与压力，较早页面则省略这两项。实时变更使用 `session/metrics` mux 帧。两种形式都携带持久日志修订号和投影修订号；客户端只接受不减小的修订号，并在向前加载较早页面时保留指标。