PUBLIC_RELAY_URL=ws://localhost:3334
PUBLIC_GROUP_ID=mygrouprandomid
PUBLIC_TITLE=            # top-bar title (full mode); empty falls back to group name
PUBLIC_MODE=simple   # simple | full
PUBLIC_JOINCODE=no   # yes | no — show invite-code field on join failure
PUBLIC_LABELS=       # comma-separated labels (e.g., bug,feature,question)
PUBLIC_BLOSSOM_URL=  # Blossom server URL (e.g., https://blossom.primal.net)