fix(install): a re-run keeps the install's existing channel (no silent switch to stable)
A re-run without --branch fell back to the stable default, which would silently switch an
existing main install onto stable. Now a re-run detects the branch the install already tracks
and stays on it; only an explicit --branch / KLONKT_BRANCH overrides, and a fresh install still
defaults to stable. The chosen channel is thus a persistent property of the install, not a
per-command default.
- scripts/install.sh — BRANCH_EXPLICIT flag (set by env KLONKT_BRANCH or --branch); on an
existing .git checkout keep the current branch unless explicitly overridden; log the channel
Co-Authored-By: Claude <noreply@…>