fix(app): normalize path separators for session diff filtering on Windows

[alexyaroshuk]

fixes #9921

What does this PR do?

Normalizes path separators when comparing file paths in the session diff filtering logic. On Windows, path.relative() returns paths with backslashes (), but Git always outputs paths with forward slashes (/). This mismatch caused modified files to be filtered out of the session review on Windows.

The fix:
Added .replaceAll("\", "/") to normalize Windows backslashes to forward slashes before comparing against Git's output.

How did you verify your code works?

On Windows, started a new session, tested modify file, delete file and create file operations.

Before

Opencode review cannot see some files have been changed

After

Fixed

[github-actions]

Hey! Your PR title fix(session diff): normalize path separators for session diff filtering on Windows doesn't follow conventional commit format.

Please update it to start with one of:

• feat: or feat(scope): new feature
• fix: or fix(scope): bug fix
• docs: or docs(scope): documentation changes
• chore: or chore(scope): maintenance tasks
• refactor: or refactor(scope): code refactoring
• test: or test(scope): adding or updating tests

Where scope is the package name (e.g., app, desktop, opencode).

See CONTRIBUTING.md for details.

[github-actions]

The following comment was made by an LLM, it may be inaccurate:

No duplicate PRs found