fix dispatcher hyphen bug in 4 more services

setup.sh's run_service() looks up install_<name> using the literal
hyphenated registered name, not an underscore-converted one. borg-backup,
calibre-web, gaming-backup, and stirling-pdf all used underscored function
names and were therefore uninstallable ("has no install_<name>"). Same
fix already applied to ai-gpu/ai-stack; this closes out the rest of the
repo-wide audit.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Nb2vJ8W7bHKx1JXVvpCraH

services/gaming-backup.sh

@@ -89,7 +89,7 @@ fi
 
 register_service gaming-backup backup "Gaming saves backup (Minecraft worlds, emulator saves, Steam)"
 
-install_gaming_backup() {
+install_gaming-backup() {
     log_info "Setting up gaming saves backup (Kopia)..."
 
     # ── Repo-conventional paths ──────────────────────────────────────────────
@@ -497,4 +497,4 @@ UNITEOF
 }
 
 # Run immediately when executed directly (deferred until after function definition)
-[[ "${_RUN_STANDALONE:-0}" == 1 ]] && install_gaming_backup
+[[ "${_RUN_STANDALONE:-0}" == 1 ]] && install_gaming-backup