feat(server,web): page the cost center's error table, abbreviate the source, drop command-tool noise (#103)

Co-authored-by: Claude Opus 5 (1M context) <noreply@anthropic.com>

packages/docs/content/server-api.en.md

@@ -141,6 +141,7 @@ On Session creation, `modelId` and `provider` are both-or-neither: send the comp
 | Method | Path | Description |
 | --- | --- | --- |
 | GET | /usage | Usage statistics; query parameters `from`, `to`, `groupBy`, `agentId`, `provider`, `modelId` |
+| GET | /usage/errors | One page of the error detail table (newest first): `offset`, `limit`, plus the same `from` / `to` / `agentId` filter → `{items, total}` |
 | GET | /agents/:agentId/traces | Date → Session drill-down structure of Trace files |
 | GET | /agents/:agentId/traces/:sessionId/:index | Read Trace events (`offset` / `limit` pagination) |
 | GET | /agents/:agentId/traces/:sessionId/:index/analysis | Trace performance analysis |

packages/docs/content/server-api.zh.md

@@ -141,6 +141,7 @@ Schedule 写操作仅限 Owner。新建 Session 模式的任务，`modelId` 与
 | 方法 | 路径 | 说明 |
 | --- | --- | --- |
 | GET | /usage | 用量统计，查询参数 `from`、`to`、`groupBy`、`agentId`、`provider`、`modelId` |
+| GET | /usage/errors | 异常明细表分页（按时间倒序）：`offset`、`limit`，以及与看板一致的 `from` / `to` / `agentId` 过滤 → `{items, total}` |
 | GET | /agents/:agentId/traces | Trace 文件的日期 → Session 下钻结构 |
 | GET | /agents/:agentId/traces/:sessionId/:index | 读取 Trace 事件（`offset` / `limit` 分页） |
 | GET | /agents/:agentId/traces/:sessionId/:index/analysis | Trace 性能分析结果 |