GitLab

- 移除 warn 级别下 access info 的强制入库补写，确保运行时日志级别真实生效

- 将 OpenAI fallback matched 与 passthrough 断流提示按需求降级为 info

- 为 codex_cli_only 与 instructions required 场景补充请求诊断字段（含 User-Agent）

- 出于安全考虑移除请求体预览，仅保留 request_body_size 与白名单头信息

- 新增/更新回归测试，覆盖 Forward 入口到日志落库链路

- gofmt: 修复 error_passthrough_service.go 格式问题
- errcheck: 修复 error_passthrough_runtime_test.go 类型断言未检查
- staticcheck: if-else 改为 switch (gateway_service.go)
- test: 修复两个测试用例错误使用 MODEL_CAPACITY_EXHAUSTED 导致走错路径

在每条错误透传规则上新增 skip_monitoring 选项，开启后匹配该规则的错误
不会被记录到 ops_error_logs，减少监控噪音。默认关闭，不影响现有规则。

Key changes:
- Upgrade model mapping: Opus 4.5 → Opus 4.6-thinking with precise matching
- Unified rate limiting: scope-level → model-level with Redis snapshot sync
- Load-balanced scheduling by call count with smart retry mechanism
- Force cache billing support
- Model identity injection in prompts with leak prevention
- Thinking mode auto-handling (max_tokens/budget_tokens fix)
- Frontend: whitelist mode toggle, model mapping validation, status indicators
- Gemini session fallback with Redis Trie O(L) matching
- Ops: enhanced concurrency monitoring, account availability, retry logic
- Migration scripts: 049-051 for model mapping unification