Remove explicit .git directory checks from executeGitCommand functions.
Git automatically searches parent directories for .git, making these
checks unnecessary and preventing subdirectory execution.
Changes:
- src/server/core/git/functions/utils.ts: Remove .git existence check
- src/server/core/git/services/GitService.ts: Remove .git existence check
- src/server/core/git/functions/getDiff.test.ts: Add subdirectory test case
Fixes#25🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>