Add git integration features: --include-logs, --include-logs-count, --no-git-sort-by-changes

Add git history integration features: --include-logs (add git commit history with messages and changed files), --include-logs-count <count> (number of recent commits to include, default 50), --no-git-sort-by-changes (don't sort files by git change frequency). Git history is valuable context for AI and sorting by changes helps prioritize recently modified files.