fix remote terminal completions

[meganrogge]

Debugging showed the completions were getting created correctly, but then were filtered out.

This was happening because we were using the local path sep instead of the one from the extension host. The fix is to pass pathSep into TerminalCompletionItem.

fixes #286155

[Copilot]

Pull request overview

This PR fixes an issue where terminal completions in remote scenarios (e.g., WSL) were incorrectly filtered out due to using the local platform's path separator instead of the remote extension host's path separator.

Key changes:

• Detects path separator from completion labels coming from the extension host
• Passes the detected path separator to TerminalCompletionItem for proper path normalization
• Removes hardcoded reliance on local platform path separator (isWindows and sep)

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 2 comments.

File	Description
src/vs/workbench/contrib/terminalContrib/suggest/browser/terminalSuggestAddon.ts	Changes _pathSeparator from hardcoded sep to detected value from completion labels; passes path separator to TerminalCompletionItem constructor; adds null checks before using path separator
src/vs/workbench/contrib/terminalContrib/suggest/browser/terminalCompletionItem.ts	Adds optional pathSeparator parameter to constructor; replaces isWindows check with explicit path separator comparison; defaults to Unix-style paths when separator is undefined

[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[Tyriar]

Possible to write a test for this?