feat(backup): kopia + borg system-config adapters (engine parity)

Mirror the restic system-config adapters for the other two engines, each in that
engine's own convention, so system backup/restore/status/retention work on any
location regardless of engine:

- kopia: BackupSystemToLocation (--tags system:config), SystemSnapshotsJson
  (filter tag system:config), RestoreSystemLatest, ForgetSystem (per-source policy
  on $configs_dir + maintenance).
- borg: BackupSystemToLocation (archive system-<host>-<ts>, comment system=config;
  no app is named "system" so the namespace can't collide), SystemSnapshotsJson
  (--glob-archives system-<host>-*), RestoreSystemLatest, ForgetSystem (prune the
  system-<host>-* glob).

No dispatcher change needed — engineBackupSystem/SystemSnapshotsJson/
RestoreSystemLatest/ForgetSystem already resolve <engine><fn> per location. All
three engines now define the full set; syntax clean.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
Signed-off-by: librelad <librelad@digitalangels.vip>

scripts/backup/engine/borg_backup.sh

@@ -50,3 +50,44 @@ borgBackupAppToLocation()
     borgEnvUnset
     return $rc
 }
+
+borgBackupSystemToLocation()
+{
+    local idx="$1"
+    local source_path="${configs_dir%/}"
+
+    if [[ ! -d "$source_path" ]]; then
+        isError "System config path missing: $source_path"
+        return 1
+    fi
+
+    borgEnvExport "$idx" || return 1
+
+    local host_tag="${CFG_INSTALL_NAME:-libreportal}"
+    # No app is named "system", so the "system-<host>-*" archive namespace can't
+    # collide with an app's archives.
+    local archive
+    archive=$(borgArchiveName "system" "$host_tag")
+    local comment="system=config host=$host_tag engine=libreportal"
+
+    local loc_name
+    loc_name=$(resticLocationName "$idx")
+    isNotice "Snapshotting system config → $loc_name (archive: $archive)" >&2
+
+    runBackupOp borg create \
+        --comment "$comment" \
+        --compression auto,zstd \
+        "::$archive" \
+        "$source_path"
+    local rc=$?
+
+    if [[ $rc -eq 0 ]]; then
+        isSuccessful "System config backed up to $loc_name: $archive" >&2
+        echo "$archive"
+    else
+        isError "System config backup to $loc_name failed" >&2
+    fi
+
+    borgEnvUnset
+    return $rc
+}

scripts/backup/engine/borg_forget.sh

@@ -38,3 +38,41 @@ borgForgetApp()
     borgEnvUnset
     return $rc
 }
+
+borgForgetSystem()
+{
+    local idx="$1"
+
+    if resticLocationAppendOnly "$idx"; then
+        isNotice "$(resticLocationName "$idx") is append-only — skipping forget for system config"
+        return 0
+    fi
+
+    local keep_last keep_daily keep_weekly keep_monthly keep_yearly
+    keep_last=$(resticRetentionFor "$idx" KEEP_LAST)
+    keep_daily=$(resticRetentionFor "$idx" KEEP_DAILY)
+    keep_weekly=$(resticRetentionFor "$idx" KEEP_WEEKLY)
+    keep_monthly=$(resticRetentionFor "$idx" KEEP_MONTHLY)
+    keep_yearly=$(resticRetentionFor "$idx" KEEP_YEARLY)
+
+    borgEnvExport "$idx" || return 1
+
+    local host_tag="${CFG_INSTALL_NAME:-libreportal}"
+    local args=(prune --glob-archives "system-${host_tag}-*")
+    [[ -n "$keep_last"    ]] && args+=(--keep-last    "$keep_last")
+    [[ -n "$keep_daily"   ]] && args+=(--keep-daily   "$keep_daily")
+    [[ -n "$keep_weekly"  ]] && args+=(--keep-weekly  "$keep_weekly")
+    [[ -n "$keep_monthly" ]] && args+=(--keep-monthly "$keep_monthly")
+    [[ -n "$keep_yearly"  ]] && args+=(--keep-yearly  "$keep_yearly")
+
+    isNotice "Applying retention for system config on $(resticLocationName "$idx")"
+    runBackupOp borg "${args[@]}"
+    local rc=$?
+
+    if [[ "$CFG_BACKUP_PRUNE_AFTER_FORGET" == "true" && $rc -eq 0 ]]; then
+        runBackupOp borg compact
+    fi
+
+    borgEnvUnset
+    return $rc
+}

scripts/backup/engine/borg_restore.sh

@@ -29,6 +29,26 @@ borgRestoreSnapshot()
     return $rc
 }
 
+borgRestoreSystemLatest()
+{
+    local idx="$1"
+    local target_dir="$2"
+    local host="${3:-$CFG_INSTALL_NAME}"
+
+    borgEnvExport "$idx" || return 1
+    local snapshot_id
+    snapshot_id=$(runBackupOp borg list --json --glob-archives "system-${host}-*" --last 1 2>/dev/null \
+        | grep -o '"name":"[^"]*"' | head -1 | cut -d'"' -f4)
+    borgEnvUnset
+
+    if [[ -z "$snapshot_id" ]]; then
+        isError "No system-config archive found in $(resticLocationName "$idx") for host=$host"
+        return 1
+    fi
+    # Whole-archive extract into staging (no include subpath).
+    borgRestoreSnapshot "$idx" "$snapshot_id" "$target_dir"
+}
+
 borgDumpFile()
 {
     local idx="$1"

scripts/backup/engine/borg_snapshots.sh

@@ -55,6 +55,50 @@ print(json.dumps(out))
     fi
 }
 
+borgSystemSnapshotsJson()
+{
+    local idx="$1"
+    local host_filter="$2"
+
+    borgEnvExport "$idx" || return 1
+
+    local glob="system-${host_filter:-*}-*"
+    local raw
+    raw=$(runBackupOp borg list --json --glob-archives "$glob" 2>/dev/null)
+    local rc=$?
+    borgEnvUnset
+    [[ $rc -ne 0 || -z "$raw" ]] && { echo "[]"; return $rc; }
+
+    if command -v jq >/dev/null 2>&1; then
+        echo "$raw" | jq -c '[.archives[] | {
+            id: .id,
+            short_id: .name,
+            time: .time,
+            hostname: .hostname,
+            tags: (.comment | split(" ") | map(select(test("^[a-z_]+=")))),
+            paths: []
+        }]'
+    else
+        echo "$raw" | python3 -c '
+import json, sys
+raw = json.load(sys.stdin)
+out = []
+for a in raw.get("archives", []):
+    comment = a.get("comment", "")
+    tags = [t for t in comment.split() if "=" in t]
+    out.append({
+        "id": a.get("id"),
+        "short_id": a.get("name"),
+        "time": a.get("time"),
+        "hostname": a.get("hostname"),
+        "tags": tags,
+        "paths": []
+    })
+print(json.dumps(out))
+' 2>/dev/null || echo "[]"
+    fi
+}
+
 borgSnapshotLatestId()
 {
     local idx="$1"

scripts/backup/engine/kopia_backup.sh

@@ -60,3 +60,41 @@ kopiaBackupAppToLocation()
     kopiaEnvUnset
     return $rc
 }
+
+kopiaBackupSystemToLocation()
+{
+    local idx="$1"
+    local source_path="${configs_dir%/}"
+
+    if [[ ! -d "$source_path" ]]; then
+        isError "System config path missing: $source_path"
+        return 1
+    fi
+
+    kopiaEnvExport "$idx" || return 1
+
+    local host_tag="${CFG_INSTALL_NAME:-libreportal}"
+    local tags=("--tags" "system:config" "--tags" "host:$host_tag" "--tags" "engine:libreportal")
+
+    local loc_name
+    loc_name=$(resticLocationName "$idx")
+    isNotice "Snapshotting system config → $loc_name (kopia)" >&2
+
+    local output
+    output=$(runBackupOp kopia snapshot create "$source_path" "${tags[@]}" --json 2>&1)
+    local rc=$?
+
+    local snapshot_id
+    snapshot_id=$(echo "$output" | grep -oE '"id":\s*"[^"]+"' | head -1 | cut -d'"' -f4)
+
+    if [[ $rc -eq 0 ]]; then
+        isSuccessful "System config backed up to $loc_name: ${snapshot_id:0:12}" >&2
+        echo "$snapshot_id"
+    else
+        isError "Kopia system config backup to $loc_name failed" >&2
+        echo "$output" | tail -10 >&2
+    fi
+
+    kopiaEnvUnset
+    return $rc
+}

scripts/backup/engine/kopia_forget.sh

@@ -41,3 +41,39 @@ kopiaForgetApp()
     kopiaEnvUnset
     return $rc
 }
+
+kopiaForgetSystem()
+{
+    local idx="$1"
+
+    if resticLocationAppendOnly "$idx"; then
+        isNotice "$(resticLocationName "$idx") is append-only — skipping forget for system config"
+        return 0
+    fi
+
+    local keep_last keep_daily keep_weekly keep_monthly keep_yearly
+    keep_last=$(resticRetentionFor "$idx" KEEP_LAST)
+    keep_daily=$(resticRetentionFor "$idx" KEEP_DAILY)
+    keep_weekly=$(resticRetentionFor "$idx" KEEP_WEEKLY)
+    keep_monthly=$(resticRetentionFor "$idx" KEEP_MONTHLY)
+    keep_yearly=$(resticRetentionFor "$idx" KEEP_YEARLY)
+
+    kopiaEnvExport "$idx" || return 1
+
+    local src="${configs_dir%/}"
+
+    local policy_args=(policy set --global=false "$src")
+    [[ -n "$keep_last"    ]] && policy_args+=(--keep-latest "$keep_last")
+    [[ -n "$keep_daily"   ]] && policy_args+=(--keep-daily "$keep_daily")
+    [[ -n "$keep_weekly"  ]] && policy_args+=(--keep-weekly "$keep_weekly")
+    [[ -n "$keep_monthly" ]] && policy_args+=(--keep-monthly "$keep_monthly")
+    [[ -n "$keep_yearly"  ]] && policy_args+=(--keep-annual "$keep_yearly")
+
+    runBackupOp kopia "${policy_args[@]}" >/dev/null 2>&1
+
+    isNotice "Running Kopia maintenance for system config on $(resticLocationName "$idx")"
+    runBackupOp kopia maintenance run --full
+    local rc=$?
+    kopiaEnvUnset
+    return $rc
+}

scripts/backup/engine/kopia_snapshots.sh

@@ -42,6 +42,61 @@ kopiaSnapshotsJson()
     fi
 }
 
+kopiaSystemSnapshotsJson()
+{
+    local idx="$1"
+    local host_filter="$2"
+
+    kopiaEnvExport "$idx" || return 1
+
+    local raw
+    raw=$(runBackupOp kopia snapshot list --all --json 2>/dev/null)
+    local rc=$?
+    kopiaEnvUnset
+    [[ $rc -ne 0 || -z "$raw" ]] && { echo "[]"; return $rc; }
+
+    local jq_filter='[.[] | {
+        id: .id,
+        short_id: (.id[0:8]),
+        time: .startTime,
+        hostname: .source.host,
+        tags: ((.tags // []) | map(sub(":"; "="))),
+        paths: [.source.path]
+    }]'
+    jq_filter='[.[] | select(any(.tags[]?; . == "system:config"))] | '"$jq_filter"
+    if [[ -n "$host_filter" ]]; then
+        jq_filter='[.[] | select(.source.host == "'"$host_filter"'")] | '"$jq_filter"
+    fi
+
+    if command -v jq >/dev/null 2>&1; then
+        echo "$raw" | jq -c "$jq_filter"
+    else
+        echo "$raw"
+    fi
+}
+
+kopiaRestoreSystemLatest()
+{
+    local idx="$1"
+    local target_dir="$2"
+    local host="${3:-$CFG_INSTALL_NAME}"
+
+    local json snapshot_id
+    json=$(kopiaSystemSnapshotsJson "$idx" "$host")
+    if command -v jq >/dev/null 2>&1; then
+        snapshot_id=$(echo "$json" | jq -r 'sort_by(.time) | last | .id // empty')
+    else
+        snapshot_id=$(echo "$json" | grep -oE '"id":\s*"[^"]+"' | tail -1 | cut -d'"' -f4)
+    fi
+
+    if [[ -z "$snapshot_id" ]]; then
+        isError "No system-config snapshot found in $(resticLocationName "$idx") for host=$host"
+        return 1
+    fi
+    # Whole-snapshot restore into staging (no include subpath).
+    kopiaRestoreSnapshot "$idx" "$snapshot_id" "$target_dir"
+}
+
 kopiaSnapshotLatestId()
 {
     local idx="$1"