fix(config): support Chinese comma separator in allow_from environment variables

[darrenzeng2025]

📝 Description

This PR fixes an issue where IRC (and other channels) allow_from configuration fails when users accidentally use Chinese comma (，) instead of English comma (,) as separators in environment variables.

The fix adds an UnmarshalText method to FlexibleStringSlice that:

• Handles comma-separated values from environment variables
• Automatically converts Chinese commas (，) to English commas (,)
• Trims whitespace from each value
• Filters out empty strings

🗣️ Type of Change

• 🐞 Bug fix (non-breaking change which fixes an issue)

🤖 AI Code Generation

• 🛠️ Mostly AI-generated (AI draft, Human verified/modified)

🔗 Related Issue

Fixes #1280

📚 Technical Context

• Reference URL: https://github.com/caarlos0/env/v11#custom-parser-funcs
• Reasoning: The env library uses encoding.TextUnmarshaler interface for custom parsing. By implementing this interface, we can handle both English and Chinese comma separators transparently.

🧪 Test Environment

• Hardware: x86_64 VM
• OS: Linux 4.19.112
• Go Version: 1.25.7 (required by project)

☑️ Checklist

• My code follows the style of this project.
• I have performed a self-review of my changes.
• The change is minimal and focused on the specific issue.
• Comments added for complex logic.

[CLAassistant]

All committers have signed the CLA.

[nikolasdehor]

The intent is good -- supporting Chinese comma (，) as a separator in environment variables is a nice UX improvement for Chinese-speaking users who may accidentally use their IME's comma.

However, a few concerns:

1. No tests -- this is a parsing change that affects allow_from, a security-sensitive configuration field. Unit tests for UnmarshalText are essential. Test cases should cover:

   • English commas only: "123,456,789"
   • Chinese commas only: "123，456，789"
   • Mixed: "123,456，789"
   • Trailing/leading commas: ",123,,456,"
   • Single value (no commas)
   • Empty string
   • Whitespace: " 123 , 456 "

2. Scope creep risk -- should this also handle Japanese comma (、), full-width comma (\uff0c which is the same as ，), or semicolons? The current implementation is focused and reasonable, but consider documenting the supported separators.

3. Interaction with JSON unmarshaling -- the existing UnmarshalJSON handles JSON arrays and numbers. The new UnmarshalText is only used by the env library for environment variable parsing. This separation is correct, but please verify that the env library calls UnmarshalText and not UnmarshalJSON when reading from environment variables.

4. Make result nil vs empty slice consistent -- when text is empty, you return nil. When text is all commas (",,,"), the result would be an empty []string{} (allocated but empty). Consider whether nil vs empty-slice matters downstream.

Please add tests and this will be ready to approve.

[darrenzeng2025]

@nicklein I've added comprehensive unit tests for the "FlexibleStringSlice.UnmarshalText" method as requested.

Tests added in "pkg/config/config_test.go":

1. TestFlexibleStringSlice_UnmarshalText - Main test covering:

   • English commas only: "123,456,789"
   • Chinese commas only: "123，456，789"
   • Mixed English and Chinese commas: "123,456，789"
   • Single value: "123"
   • Values with whitespace trimming
   • Empty string (returns nil)
   • Only commas - returns empty slice
   • Mixed commas with empty parts
   • Complex values like email addresses

2. TestFlexibleStringSlice_UnmarshalText_EmptySliceConsistency - Tests the distinction between:

   • Empty string → returns nil
   • Commas only → returns empty slice (not nil)

All tests have been verified to pass. The PR should now be ready for review and merge.

Note: There may still be conflicts in docker-compose.yml that need to be resolved via rebase if the base branch has changed.

[darrenzeng2025]

✅ Update: Conflicts resolved!

The docker-compose.yml conflict has been resolved by rebasing onto the latest upstream/main. The PR now includes both:

• The upstream "picoclaw-launcher" service
• Our "picoclaw-gateway-dev" service (with dev profile)

The PR should now be mergeable. Please review when you have a chance.

[darrenzeng2025]

✅ 分支已清理！

已移除与 PR #1301 无关的文件修改（Dockerfile.dev 和 docker-compose.yml 的更改）。

现在 PR 只包含以下修改：

• "pkg/config/config.go" - 中文逗号分隔符的 UnmarshalText 实现
• "pkg/config/config_test.go" - 全面的单元测试

PR 现在干净整洁，只关注解决中文逗号分隔符的问题。

[yinwm]

Review Summary

This PR correctly fixes a real user pain point for CJK users who accidentally use Chinese commas in environment variables. The implementation is clean and well-tested.

✅ What's Good

• Correctly implements encoding.TextUnmarshaler interface
• Comprehensive test coverage (English/Chinese/mixed commas, whitespace, edge cases)
• Clear comments explaining the purpose
• Backward compatible

💡 Suggestions for Future Improvement

1. nil vs empty slice inconsistency: Empty string returns nil, but comma-only input returns []string{}. Consider unifying the behavior.

2. JSON config support: UnmarshalText only handles environment variables. If users configure via JSON file or Web UI with Chinese commas, UnmarshalJSON won't handle it. Consider adding similar support there if needed.

3. Integration test: Consider adding a test that verifies the env library correctly parses PICOCLAW_CHANNELS_IRC_ALLOW_FROM="123，456".

These are minor suggestions and do not block merging. Thanks for the fix!