fix: add relay idle connection timeout config

[seefs001]

⚠️ 提交说明 / PR Notice

Important

• 请提供人工撰写的简洁摘要，避免直接粘贴未经整理的 AI 输出。

📝 变更描述 / Description

(简述：做了什么？为什么这样改能生效？请基于你对代码逻辑的理解来写，避免粘贴未经整理的内容)

支持配置http client的idle timeout，默认为golang net/http的默认值90s

环境变量 RELAY_IDLE_CONN_TIMEOUT

🚀 变更类型 / Type of change

• 🐛 Bug 修复 (Bug fix) - 请关联对应 Issue，避免将设计取舍、理解偏差或预期不一致直接归类为 bug
• ✨ 新功能 (New feature) - 重大特性建议先通过 Issue 沟通
• ⚡ 性能优化 / 重构 (Refactor)
• 📝 文档更新 (Documentation)

🔗 关联任务 / Related Issue

• Related Anthropic(OpenRouter) 渠道持续返回 region 403，重启应用后恢复 #5233 一段时间不访问，web端渠道测试卡死，外部curl失败报错500，curl一次后恢复正常 #3448 feat: 配置 HTTP/2 PING 保活机制，防止空闲连接被中间设备 RST #5308

✅ 提交前检查项 / Checklist

• 人工确认: 我已亲自整理并撰写此描述，没有直接粘贴未经处理的 AI 输出。
• 非重复提交: 我已搜索现有的 Issues 与 PRs，确认不是重复提交。
• Bug fix 说明: 若此 PR 标记为 Bug fix，我已提交或关联对应 Issue，且不会将设计取舍、预期不一致或理解偏差直接归类为 bug。
• 变更理解: 我已理解这些更改的工作原理及可能影响。
• 范围聚焦: 本 PR 未包含任何与当前任务无关的代码改动。
• 本地验证: 已在本地运行并通过测试或手动验证，维护者可以据此复核结果。
• 安全合规: 代码中无敏感凭据，且符合项目代码规范。

📸 运行证明 / Proof of Work

(请在此粘贴截图、关键日志或测试报告，以证明变更生效)

Summary by CodeRabbit

• New Features

  • Added support for configuring idle connection timeout in relay HTTP clients. Users can now set RELAY_IDLE_CONN_TIMEOUT environment variable (default: 90 seconds) to customize idle keep-alive timeout; set to 0 to disable.

• Documentation

  • Updated README and environment configuration examples with new relay timeout setting.

[coderabbitai]

Walkthrough

A new idle connection timeout configuration is introduced for relay HTTP clients. The setting is declared as a global constant, initialized from the RELAY_IDLE_CONN_TIMEOUT environment variable with a 90-second default, documented in configuration examples and the README, and applied uniformly to all HTTP transport instances used by the service.

Changes

Relay Idle Connection Timeout Configuration

Layer / File(s)	Summary
Configuration constant declaration common/constants.go	New exported variable RelayIdleConnTimeout (int, seconds) is declared alongside other relay timeout settings.
Configuration documentation and examples .env.example, README.md, docker-compose.yml	Configuration examples and deployment documentation are updated to describe RELAY_IDLE_CONN_TIMEOUT, its default of 90 seconds, and how to disable it with 0.
Configuration initialization common/init.go	Environment variable RELAY_IDLE_CONN_TIMEOUT is read during InitEnv() and stored in RelayIdleConnTimeout using GetEnvOrDefault with default 90.
HTTP transport idle timeout application service/http_client.go	The configured timeout is applied to the IdleConnTimeout field of three HTTP transport instances: base client, HTTP/HTTPS proxy client, and SOCKS5/SOCKS5H proxy client, each converted to time.Duration.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Poem

🐰 A timeout so fine, for connections idle—
ninety seconds by default, no need to whittle.
Through env vars and proxies, the config flows free,
from constant to transport, a timeout decree! 🌰

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 33.33% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: adding relay idle connection timeout configuration across multiple files.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

• Create PR with unit tests

---

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

• X
• Mastodon
• Reddit
• LinkedIn

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

[coderabbitai]

Actionable comments posted: 3

🤖 Prompt for all review comments with AI agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In @.env.example:
- Around line 59-60: The comment for RELAY_IDLE_CONN_TIMEOUT is ambiguous about
whether it dynamically follows Go's stdlib or is a fixed default; update the
.env.example comment to state the explicit default used by the code: mention
"默认为 90 秒（与 Go 标准库一致）" so it matches the behavior from
GetEnvOrDefault("RELAY_IDLE_CONN_TIMEOUT", 90) in common/init.go and references
RELAY_IDLE_CONN_TIMEOUT clearly.

In `@docker-compose.yml`:
- Line 37: Update the commented description for RELAY_IDLE_CONN_TIMEOUT to
reflect the actual default used in code: change "默认跟随 Go 标准库" to "默认为 90 秒（与 Go
标准库一致）" so the docker-compose comment matches the hardcoded default in
common/init.go (see the 90s default set in common/init.go:105) and clearly
indicate the unit is seconds and that 0 disables the limit.

In `@README.md`:
- Line 319: Update the README entry for RELAY_IDLE_CONN_TIMEOUT to explicitly
state the hardcoded default of 90 seconds rather than saying "Go standard
library behavior"; change the description to something like "Idle keep-alive
timeout for relay HTTP clients, seconds. Default is 90 (matching Go standard
library); set 0 to disable" so it matches the actual default set in the code
where RELAY_IDLE_CONN_TIMEOUT is initialized.

🪄 Autofix (Beta)

Fix all unresolved CodeRabbit comments on this PR:

• Push a commit to this branch (recommended)
• Create a new PR with the fixes

---

ℹ️ Review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 07856e2e-6f32-46fc-a3c1-9d68223c5354

📥 Commits

Reviewing files that changed from the base of the PR and between 87cc22d and 316b621.

📒 Files selected for processing (6)

• .env.example
• README.md
• common/constants.go
• common/init.go
• docker-compose.yml
• service/http_client.go

[coderabbitai]

⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Clarify the default behavior description.

The comment states "默认跟随 Go 标准库" (defaults to Go standard library), but looking at common/init.go:105, the code explicitly sets GetEnvOrDefault("RELAY_IDLE_CONN_TIMEOUT", 90). While 90 seconds matches Go's http.Transport default, the current phrasing suggests the value dynamically follows the standard library rather than being hardcoded. Consider revising to: "默认为 90 秒（与 Go 标准库一致）" (defaults to 90 seconds, matching Go standard library) for clarity.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In @.env.example around lines 59 - 60, The comment for RELAY_IDLE_CONN_TIMEOUT
is ambiguous about whether it dynamically follows Go's stdlib or is a fixed
default; update the .env.example comment to state the explicit default used by
the code: mention "默认为 90 秒（与 Go 标准库一致）" so it matches the behavior from
GetEnvOrDefault("RELAY_IDLE_CONN_TIMEOUT", 90) in common/init.go and references
RELAY_IDLE_CONN_TIMEOUT clearly.

[coderabbitai]

⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Clarify the default behavior description.

The comment states "默认跟随 Go 标准库" (defaults to Go standard library), but the code in common/init.go:105 explicitly sets a hardcoded default of 90 seconds. Consider revising to: "默认为 90 秒（与 Go 标准库一致）" (defaults to 90 seconds, matching Go standard library) to accurately reflect the implementation.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@docker-compose.yml` at line 37, Update the commented description for
RELAY_IDLE_CONN_TIMEOUT to reflect the actual default used in code: change "默认跟随
Go 标准库" to "默认为 90 秒（与 Go 标准库一致）" so the docker-compose comment matches the
hardcoded default in common/init.go (see the 90s default set in
common/init.go:105) and clearly indicate the unit is seconds and that 0 disables
the limit.

[coderabbitai]

⚠️ Potential issue | 🟡 Minor | ⚡ Quick win

Clarify the default behavior description.

The description states "Defaults to Go standard library behavior" but common/init.go:105 explicitly hardcodes the default to 90 seconds. While this value matches Go's http.Transport default, the current wording suggests dynamic behavior. Consider revising to: "Idle keep-alive timeout for relay HTTP clients, seconds. Default is 90 (matching Go standard library); set 0 to disable" for clarity.

🤖 Prompt for AI Agents

Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

In `@README.md` at line 319, Update the README entry for RELAY_IDLE_CONN_TIMEOUT
to explicitly state the hardcoded default of 90 seconds rather than saying "Go
standard library behavior"; change the description to something like "Idle
keep-alive timeout for relay HTTP clients, seconds. Default is 90 (matching Go
standard library); set 0 to disable" so it matches the actual default set in the
code where RELAY_IDLE_CONN_TIMEOUT is initialized.