fix: call `ccusage` with user shell instead of golang minimal env

[AnnatarHe]

In file model/ccusage_service.go, lines 237 and 242, the command just calls npx or bunx in a minimal environment. Maybe you can try to get the user's shell first and use the shell to call the command instead of just calling the commands directly. @claude

[claude]

Claude finished @AnnatarHe's task —— View job • claude/issue-127-20251005-0754 • Create PR ➔

---

Task completed ✓

Summary

Fixed the ccusage command execution to use the user's shell environment instead of Go's minimal environment. This ensures that npx and bunx commands have access to proper PATH and environment variables.

Changes Made

• Added getUserShell() function (lines 421-444): Detects user's shell from $SHELL environment variable with platform-specific fallbacks (PowerShell/cmd for Windows, /bin/sh for Unix)
• Added shellEscapeArgs() function (lines 446-454): Safely escapes shell arguments by wrapping them in single quotes
• Modified command execution (lines 234-249): Commands now execute via shell -c "command args" instead of direct execution

Technical Details

The issue was that exec.CommandContext(ctx, "npx", args...) runs commands in a minimal environment without the user's shell configuration. By using exec.CommandContext(ctx, shell, "-c", cmdStr), commands now run in the user's shell with full environment.

Note: Pre-existing build errors in model/ai_service.go are unrelated to this fix.

Next Steps

--- |