Feature: Configurable Terminals in Standalone Mode

[thomas-intramotev]

Summary

Implements #8: support for configurable Terminal emulators in which to open conversations from Standalone mode.

Example config for Git Bash on Windows:

# ~/config.json
{
  "customTerminals": [
    {
      "command": "C:\\Program Files\\Git\\git-bash.exe", # Claudine implicitly sets cwd to conversation workspace
      "args": ["-c"] # Claudine implicitly appends e.g. 'claude --resume <session-id>`
    }
  ]
}

I do recommend that this be tested on Linux and macOS before merging, as I've only had the chance to test on Windows thus far.

Changes

• Adds customTerminals optional configuration property.
• Normalizes tryExecFiles strategy in StandaloneMessageHandler.ts so that all platforms encode a list of preconfigured terminal emulators, and working directory is specified in execFile arguments rather than as part of the command.
• Prepends custom terminal configs to the platform-specific list so that custom terminals are prioritized, but Claudine falls back on opening preconfigured terminals.

Unrelated to feature:

• Untracks files under out-standalone/: these were in the .gitignore, but seems they'd already been set up to track.

• Adds a VS Code launch configuration to debug unit tests...I've been experiencing a transient error where some unit tests, namely

  • 'Conversation Parser' > 'rate limit detection' > 'detects rate limit in assistant text'
  • 'Conversation Parser' > 'rate limit detection' > 'detects rate limit in tool_result text'

  and possibly others will non-deterministically fail, but I can't reproduce it reliably enough to debug.

Checklist

• npm test passes
• npm run lint passes
• Webview builds (cd webview && npm run build)
• Tested manually in the Extension Development Host
• Updated CHANGELOG.md (if user-facing change)
• User-facing strings use vscode.l10n.t() for i18n