feat(backup): apps-pg restore drill + close WP-0014

Add tools/apps-pg-restore-drill.sh and make target; T04 evidence for
vergabe_db row-count gate. Archive finished RAILIANCE-WP-0014.

tools/apps-pg-restore-drill.sh

@@ -0,0 +1,101 @@
+#!/usr/bin/env bash
+# Isolated apps-pg restore drill for vergabe_db (RAILIANCE-WP-0013-T04).
+# Restores a local pg_dump into a temporary database on the apps-pg cluster.
+set -euo pipefail
+
+APPS_PG_NAMESPACE="${APPS_PG_NAMESPACE:-databases}"
+APPS_PG_CLUSTER="${APPS_PG_CLUSTER:-apps-pg}"
+APPS_PG_POD="${APPS_PG_POD:-}"
+SOURCE_DB="${APPS_PG_DATABASE:-vergabe_db}"
+BACKUP_DIR="${BACKUP_DIR:-$HOME/.cache/railiance/backups/apps-pg}"
+BACKUP_FILE="${APPS_PG_BACKUP_FILE:-}"
+DRILL_DB="${APPS_PG_RESTORE_DB:-vergabe_restore_drill}"
+EVIDENCE_DIR="${EVIDENCE_DIR:-$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)/docs/evidence}"
+
+if [[ -z "$APPS_PG_POD" ]]; then
+  APPS_PG_POD="$(
+    kubectl get pods -n "$APPS_PG_NAMESPACE" \
+      -l "cnpg.io/cluster=${APPS_PG_CLUSTER},role=primary" \
+      -o jsonpath='{.items[0].metadata.name}' 2>/dev/null || true
+  )"
+fi
+if [[ -z "$APPS_PG_POD" ]]; then
+  echo "ERROR: primary pod for ${APPS_PG_CLUSTER} not found" >&2
+  exit 1
+fi
+
+if [[ -z "$BACKUP_FILE" ]]; then
+  BACKUP_FILE="$(
+    find "$BACKUP_DIR" -maxdepth 1 -name "apps-pg-${SOURCE_DB}-*.dump" -type f 2>/dev/null \
+      | sort -r | head -1
+  )"
+fi
+if [[ -z "$BACKUP_FILE" || ! -f "$BACKUP_FILE" ]]; then
+  echo "ERROR: no backup file found for ${SOURCE_DB} under ${BACKUP_DIR}" >&2
+  echo "Run: make apps-pg-backup-dry-run" >&2
+  exit 1
+fi
+
+psql_exec() {
+  kubectl exec -n "$APPS_PG_NAMESPACE" "$APPS_PG_POD" -c postgres -- \
+    psql -U postgres -v ON_ERROR_STOP=1 "$@"
+}
+
+count_tables() {
+  local db="$1"
+  psql_exec -d "$db" -Atc \
+    "SELECT COALESCE(SUM(n_live_tup),0)::bigint FROM pg_stat_user_tables;"
+}
+
+echo "apps-pg restore drill"
+echo "  cluster:  ${APPS_PG_CLUSTER}"
+echo "  pod:      ${APPS_PG_POD}"
+echo "  source:   ${SOURCE_DB}"
+echo "  backup:   ${BACKUP_FILE}"
+echo "  drill db: ${DRILL_DB}"
+echo
+
+psql_exec -d postgres -c "DROP DATABASE IF EXISTS \"${DRILL_DB}\";"
+psql_exec -d postgres -c "CREATE DATABASE \"${DRILL_DB}\";"
+echo "ok: created drill database ${DRILL_DB}"
+
+kubectl exec -i -n "$APPS_PG_NAMESPACE" "$APPS_PG_POD" -c postgres -- \
+  pg_restore -U postgres -d "$DRILL_DB" --no-owner --no-acl --clean --if-exists \
+  < "$BACKUP_FILE"
+echo "ok: pg_restore completed"
+
+PROD_ROWS="$(count_tables "$SOURCE_DB")"
+DRILL_ROWS="$(count_tables "$DRILL_DB")"
+echo "row estimate — production ${SOURCE_DB}: ${PROD_ROWS}"
+echo "row estimate — drill ${DRILL_DB}:       ${DRILL_ROWS}"
+
+if [[ "$PROD_ROWS" != "$DRILL_ROWS" ]]; then
+  echo "ERROR: row-count mismatch between production and restore drill" >&2
+  exit 1
+fi
+echo "ok: row-count gate passed"
+
+TS="$(date -u +%Y%m%dT%H%M%SZ)"
+mkdir -p "$EVIDENCE_DIR"
+EVIDENCE_FILE="${EVIDENCE_DIR}/apps-pg-restore-drill-${TS}.json"
+python3 - <<PY
+import json, pathlib
+payload = {
+    "captured_at": "${TS}",
+    "workplan": "RAILIANCE-WP-0013",
+    "cluster": "${APPS_PG_CLUSTER}",
+    "source_database": "${SOURCE_DB}",
+    "restore_database": "${DRILL_DB}",
+    "backup_file": "$(basename "$BACKUP_FILE")",
+    "production_row_estimate": int("${PROD_ROWS}"),
+    "restored_row_estimate": int("${DRILL_ROWS}"),
+    "row_count_gate": "pass",
+    "notes": "Isolated restore on live CNPG primary; drill DB dropped after evidence write.",
+}
+path = pathlib.Path("${EVIDENCE_FILE}")
+path.write_text(json.dumps(payload, indent=2) + "\\n", encoding="utf-8")
+print(f"ok: evidence {path}")
+PY
+
+psql_exec -d postgres -c "DROP DATABASE IF EXISTS \"${DRILL_DB}\";"
+echo "ok: dropped drill database ${DRILL_DB}"