refactor: move backup/restore worker scripts to extras/ as source files

Replace embedded heredocs in the three backup service installers with
cp from versioned source files in extras/:

  extras/backup_kopia.sh   — Kopia worker (was inline in services/backup.sh)
  extras/backup_borg.sh    — Borg worker  (was inline in services/borg-backup.sh)
  extras/backup_gaming.sh  — gaming saves worker (was inline in services/gaming-backup.sh)
  extras/restore_kopia.sh  — unified Kopia restore (multi-dest + single-dest)
  extras/restore_borg.sh   — unified Borg restore with destination picker

Each installer now does `cp extras/<script>.sh $DIR/<script>.sh` instead of
writing the script inline. Workers and restore scripts are now readable in the
repo rather than buried in heredocs.

Restore scripts are installed flat into the service directory root:
  ~/docker/backup/backup_kopia.sh   ~/docker/backup/restore_kopia.sh
  ~/docker/borg-backup/backup_borg.sh   ~/docker/borg-backup/restore_borg.sh
  ~/docker/gaming-backup/backup_gaming.sh   ~/docker/gaming-backup/restore_kopia.sh

The new restore scripts handle destination selection internally, so a single
script replaces the old per-destination restore/<dest>/ layout.

Also fixes `local` used outside a function in restore_kopia.sh and
restore_borg.sh (destination picker loop), and removes the now-superseded
extras/restore_kopia_backup.sh and extras/restore_borg_backup.sh.

https://claude.ai/code/session_019XgsQ13XKm4Zj3cNsDNwHj

extras/backup_kopia.sh

@@ -0,0 +1,120 @@
+#!/bin/bash
+# extras/backup_kopia.sh — Kopia backup worker for all Docker services.
+# Installed to ~/docker/backup/backup_kopia.sh by the backup service installer.
+#
+#   sudo ./backup_kopia.sh             run a full backup cycle
+#   sudo ./backup_kopia.sh snapshots   list all snapshots (all repos)
+#   sudo ./backup_kopia.sh policy      show retention policies
+#
+# Minecraft instances: flush to disk (save-all) then snapshot — no downtime.
+# All other services:  stop → snapshot → restart for consistency.
+# Reads backup.conf from the same directory.
+set -uo pipefail
+
+HERE="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+CONF="${BACKUP_CONF:-$HERE/backup.conf}"
+[ -f "$CONF" ] || { echo "Config not found: $CONF  (re-run: sudo setup.sh backup)"; exit 1; }
+# shellcheck source=/dev/null
+source "$CONF"
+
+ACTUAL_USER="${SUDO_USER:-${USER:-$(id -un)}}"
+ACTUAL_HOME="$(getent passwd "$ACTUAL_USER" 2>/dev/null | cut -d: -f6 || echo "/home/$ACTUAL_USER")"
+DOCKER_DIR="$ACTUAL_HOME/docker"
+
+log() { echo "[$(date '+%F %T')] $*"; }
+
+kp_for() {
+    local dest="$1"; shift
+    local cfg_var="DEST_${dest}_CONFIG" pw_var="DEST_${dest}_PASSWORD"
+    local cfg="${!cfg_var:-}" pw="${!pw_var:-}"
+    [ -n "$cfg" ] || { log "Unknown destination: $dest"; return 1; }
+    env KOPIA_PASSWORD="$pw" "$KOPIA" --config-file="$cfg" "$@"
+}
+
+dest_for_svc() {
+    local var="SVC_${1//-/_}"
+    echo "${!var:-${DEST_DEFAULT:-default}}"
+}
+
+is_minecraft() { [ -f "${1}Dockerfile" ] && grep -qs itzg "${1}Dockerfile"; }
+
+case "${1:-run}" in
+    snapshots)
+        for dest in ${DEST_NAMES:-default}; do
+            echo ""; echo "── dest: $dest ──"
+            kp_for "$dest" snapshot list 2>/dev/null || true
+        done
+        exit 0 ;;
+    policy)
+        for dest in ${DEST_NAMES:-default}; do
+            echo ""; echo "── dest: $dest ──"
+            kp_for "$dest" policy show --global 2>/dev/null || true
+        done
+        exit 0 ;;
+esac
+
+log "===== Backup starting ====="
+rc=0
+
+for svc_dir in "$DOCKER_DIR"/*/; do
+    [ -f "${svc_dir}docker-compose.yml" ] || continue
+    svc="$(basename "$svc_dir")"
+    [[ "$svc" == "backup" || "$svc" == "borg-backup" || "$svc" == "gaming-backup" ]] && continue
+
+    dest="$(dest_for_svc "$svc")"
+    _repo_var="DEST_${dest}_REPO"
+    [ -n "${!_repo_var:-}" ] || { log "SKIP $svc — dest '$dest' not configured in conf"; continue; }
+
+    if is_minecraft "$svc_dir"; then
+        if docker ps --format '{{.Names}}' 2>/dev/null | grep -qx "$svc"; then
+            log "Flushing Minecraft world '$svc' (save-all, no downtime)..."
+            docker exec "$svc" mc-send-to-console save-all flush 2>/dev/null \
+                || docker exec "$svc" rcon-cli save-all 2>/dev/null || true
+            sleep 5
+        fi
+        log "Snapshotting $svc (dest: $dest)..."
+        if kp_for "$dest" snapshot create --description="backup: $svc" "$svc_dir"; then
+            log "OK $svc (Minecraft, no downtime)"
+        else
+            log "WARNING: snapshot failed for $svc"; rc=1
+        fi
+    else
+        STOPPED=false
+        if docker ps --format '{{.Names}}' 2>/dev/null | grep -qx "$svc"; then
+            log "Stopping $svc..."
+            docker compose -f "${svc_dir}docker-compose.yml" down 2>/dev/null \
+                || docker stop "$svc" 2>/dev/null \
+                || log "WARNING: could not stop $svc — snapshotting live (consistency not guaranteed)"
+            STOPPED=true
+        fi
+
+        log "Snapshotting $svc (dest: $dest)..."
+        if kp_for "$dest" snapshot create --description="backup: $svc" "$svc_dir"; then
+            log "OK $svc"
+        else
+            log "WARNING: snapshot failed for $svc"; rc=1
+        fi
+
+        if [ "$STOPPED" = true ]; then
+            log "Starting $svc..."
+            docker compose -f "${svc_dir}docker-compose.yml" up -d 2>/dev/null \
+                || log "WARNING: could not restart $svc — run: docker compose -f ${svc_dir}docker-compose.yml up -d"
+        fi
+    fi
+done
+
+if [ "${REMOTE_TYPE:-none}" != "none" ] && [ -n "${REMOTE_TYPE:-}" ]; then
+    for dest in ${DEST_NAMES:-default}; do
+        log "Mirroring '$dest' offsite ($REMOTE_TYPE)..."
+        # shellcheck disable=SC2086
+        kp_for "$dest" repository sync-to "$REMOTE_TYPE" $REMOTE_ARGS \
+            || { log "WARNING: mirror failed for '$dest'"; rc=1; }
+    done
+fi
+
+if [ "$rc" -eq 0 ]; then
+    log "===== Backup complete ====="
+else
+    log "===== Backup finished WITH WARNINGS (see above) ====="
+fi
+exit "$rc"