Document dataconnect environment options and add branch-cleaning tooling. Adds PROTECTED_BRANCHES.md listing protected branches (main, dev, demo/**). Updates Makefile help text to show ENV defaults for dataconnect targets, new bootstrap/backup/validation commands, and a tip about default ENV. Adds a new clean-branches .PHONY target in makefiles/tools.mk that validates the current branch, reads PROTECTED_BRANCHES.md, prompts for confirmation, switches to dev if necessary, and deletes non-protected local branches while reporting a summary.
