Windows support: CRLF in .contextignore + path-separator assumptions

[egorfedorov]

Problem

CCO assumes POSIX. On Windows it will misbehave:

• src/contextignore.js:40 — content.split('\n') leaves a trailing \r on CRLF files, so every .contextignore pattern silently fails to match.
• globToRegex / path matching assume / separators; Windows paths use \.
• getProjectRoot() walks up assuming /-rooted paths (utils.js).

Why it matters

Windows is a large share of Claude Code users; right now the ignore-list and project-root detection are effectively broken there, degrading every downstream feature.

Proposal

• Normalize line endings: split(/\r?\n/) in _parseIgnoreFile.
• Normalize path separators to / before glob matching; use path.sep-aware logic in getProjectRoot.
• Add tests with CRLF fixtures and Windows-style paths.

Affected

src/contextignore.js, src/utils.js

Acceptance

• .contextignore matches identically given LF or CRLF input.
• Path/glob tests pass with both / and \ separators.