Adds a new 'bd reset' command that completely removes beads from a repository: - Stops running daemon - Removes git hooks (pre-commit, post-merge, pre-push, post-checkout) - Removes merge driver configuration - Removes .gitattributes entry - Removes sync branch worktrees - Removes .beads directory By default runs in dry-run mode showing what would be deleted. Use --force to actually perform the reset. Closes steveyegge/beads#505