[homniloquy]

Summary / 概述

The dashboard log window's "upstream model" column rendered ProxyRequest.model, which chat.ts fills with a display name: buildDisplayModelName() re-appends the -high / -fast suffixes parseModelName() had just stripped. A request for gpt-6-high was therefore logged as gpt-6-astra-high while the wire actually carried gpt-6-astra — the audit trail named a model that was never requested upstream.

日志窗口的「出口模型」列读取的是 ProxyRequest.model，而该字段是 chat.ts 用 buildDisplayModelName() 生成的展示名——它会把 parseModelName() 刚剥掉的 -high / -fast 后缀重新拼回。于是 gpt-6-high 被记成 gpt-6-astra-high，而实际请求上游的模型是 gpt-6-astra，日志因此显示了一个从未真正请求过的模型。

Changes / 改动

• Add upstreamModelOf(), returning the resolved id the translation layer actually sent, and route every egress audit row through it — Codex account path, direct / fallback path, and the stream-close rows (client-abort, upstream-premature, client-write-failed). / 新增 upstreamModelOf()，返回翻译层实际写出的模型 ID，并让所有出口审计行改走它——账号路径、直连/fallback 路径，以及 stream-close 各行。
• Split the two concerns streamResponse()'s model parameter conflated: model stays the client-facing echo, a new optional upstreamModel feeds the audit rows (defaults to model, so the Ollama bridge caller is unaffected). / 拆分 streamResponse() 的 model 参数原先兼管的两种语义：model 继续用于客户端回显，新增可选 upstreamModel 供审计行使用（缺省回落到 model，Ollama 桥调用方无需改动）。
• No new suffix parsing is introduced — the resolver's output is reused, as the issue requested — so a model whose real id ends in an effort word is still reported verbatim. Ingress rows, the client-facing echo, and reasoning-effort / fast-tier / routing behavior are unchanged. / 未新增任何后缀解析（按 issue 要求复用既有解析逻辑），真实 id 以 effort 词结尾的模型仍原样上报；入口行、客户端回显、推理等级 / 快速模式 / 路由行为均未改动。
• Regression coverage: new tests/unit/routes/shared/direct-egress-model.test.ts driving handleDirectRequest, plus resolver-driven cases in proxy-egress-log.test.ts; two pre-existing tests that asserted the old display-name behavior were corrected. / 回归覆盖：新增 direct-egress-model.test.ts，并在 proxy-egress-log.test.ts 补充驱动真实解析器的用例；两个固化旧行为的既有测试一并修正。
• Recorded in CHANGELOG.md. / 已记入 CHANGELOG.md。

Test Plan / 验证

• npx tsc --noEmit — passed / 通过
• npm test — 325 files passed; 3423 tests passed, 1 skipped / 325 个文件通过、3423 项测试通过、1 项跳过
• npm run build — passed / 通过
• git diff --check — passed / 通过
• Manual end-to-end against a local mock Responses-API upstream: gpt-6-high / gpt-6-fast / gpt-6-astra all log gpt-6-astra on the egress row (matching the wire) while the ingress row keeps the raw name. / 实机端到端：对本地 mock 上游发起请求，出口行均显示 gpt-6-astra（与线上一致），入口行保留原始名称。
• Mutation check: reverting upstreamModelOf() to its old body turns the new cases red while the "no suffix" and "legitimate suffix" controls stay green. / 变异检查：改回旧实现后新增用例变红，两个对照用例仍为绿。
• npm run test:real — not run; the change is confined to audit logging under src/routes/shared/ and does not touch the upstream protocol (translation/, proxy/, auth/). / 未运行：本次改动仅涉及审计日志，未触及上游协议层。

Linked Issues / 关联 issue

Closes #848

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This PR targets dev for review and does not deploy or merge. / 本 PR 仅提交至 dev 供检查，未部署或合并。

[SsuJojo]

Superseded by merged PR #864, which reapplied this change on the current dev baseline and passed CI.