docs: add CPA-Manager to usage statistics recommendations

[seakee]

Summary

Add CPA-Manager to the Usage Statistics recommendations in all README variants.

Changes

• Add CPA-Manager to the English, Chinese, and Japanese Usage Statistics sections
• Highlight request-level monitoring, cost estimates, LiteLLM price sync, SQLite persistence, and Codex account-pool operations

Testing

• git diff --check

[github-actions]

This pull request targeted main.

The base branch has been automatically changed to dev.

[gemini-code-assist]

Code Review

This pull request adds documentation for CPA-Manager to the English, Chinese, and Japanese README files, describing it as a management center for CLIProxyAPI with features such as request monitoring, cost estimation, and account pool maintenance. The review feedback suggests improving the Chinese documentation by capitalizing technical terms like 'Token' and adding spaces between Chinese and English characters to ensure consistency and better readability.

[gemini-code-assist]

In the Chinese documentation, it is standard practice to capitalize technical terms like "Token" and include spaces between Chinese characters and English words for better readability. Additionally, line 79 already uses "Token" (capitalized and with spaces), so this change ensures internal consistency.

Suggested change

	面向 CLIProxyAPI 的完整管理中心，提供请求级监控和费用预估。CPA-Manager 可按账号、模型、渠道、延迟、状态和 token 用量追踪采集到的请求；支持可编辑模型价格与一键同步 LiteLLM 价格来估算费用；用 SQLite 持久化事件；并提供面向 Codex 账号池的批量巡检、配额识别、异常账号定位、清理建议与一键执行能力，适合多账号池的日常运维管理。
	面向 CLIProxyAPI 的完整管理中心，提供请求级监控和费用预估。CPA-Manager 可按账号、模型、渠道、延迟、状态和 Token 用量追踪采集到的请求；支持可编辑模型价格与一键同步 LiteLLM 价格来估算费用；用 SQLite 持久化事件；并提供面向 Codex 账号池的批量巡检、配额识别、异常账号定位、清理建议与一键执行能力，适合多账号池的日常运维管理。

[lulavc7221]

Can translate to PT-BR too