refactor(db): JSON columns are decoded through one declared schema per column

decodeJson/decodeJsonResult/encodeJson read and write a JSON-in-TEXT column against the schema and fallback declared for it in db/json-columns.ts, and log a row that does not decode. reservations.metadata, the OAuth scope and redirect lists, consents, API token scopes, MFA backup codes, journey entry tags and pros/cons and poll options go through it. Readers that used to throw on a broken row (a hotel update, the ICS export, the price mirror, the OAuth token and session reads, a consent, a journey entry, a poll) now take the tolerant fallback the other readers of the same column already used.

server/src/nest/integrations/airtrail-import.service.ts

@@ -14,6 +14,8 @@ import { AirtrailRequestError, type AirtrailFlightRaw } from './airtrail.client'
 import { AirtrailClient } from './airtrail.client';
 import { AirtrailService } from './airtrail.service';
 import { canonicalHash, mapFlightToReservation, mapFlightsToMultiLegReservation, normalizeFlight } from './airtrail.mapper';
+import { RESERVATION_METADATA } from '../../db/json-columns';
+import { decodeJson } from '../../utils/json-column';
 
 interface ExistingFlightRow {
   id: number;
@@ -165,12 +167,8 @@ export class AirtrailImportService {
     const linkedRows = await this.reservationsRepo.listAirtrailLinkedForTrip(tripIdNum);
     for (const row of linkedRows) {
       if (row.external_id) linkedIds.add(row.external_id);
-      try {
-        const ids = row.metadata ? JSON.parse(row.metadata).airtrail_ids : null;
-        if (Array.isArray(ids)) for (const id of ids) linkedIds.add(String(id));
-      } catch {
-        /* malformed metadata — ignore */
-      }
+      const ids = decodeJson(RESERVATION_METADATA, row.metadata, `airtrail ${row.external_id}`).airtrail_ids;
+      if (Array.isArray(ids)) for (const id of ids) linkedIds.add(String(id));
     }
 
     const existing = await this.reservationsRepo.listFlightReservationsForTrip(tripIdNum);
@@ -194,12 +192,7 @@ export class AirtrailImportService {
 
     const existingSigs = new Set<string>();
     for (const row of existing) {
-      let meta: Record<string, any> = {};
-      try {
-        meta = row.metadata ? JSON.parse(row.metadata) : {};
-      } catch {
-        /* malformed metadata — ignore */
-      }
+      const meta = decodeJson(RESERVATION_METADATA, row.metadata, `reservation ${row.id}`);
       const eps = endpointsByReservation.get(row.id) ?? [];
       const legs: any[] | null = Array.isArray(meta.legs) ? meta.legs : null;
       if (legs && legs.length > 1) {
@@ -218,7 +211,7 @@ export class AirtrailImportService {
       } else {
         const from = eps[0]?.code ?? null;
         const to = eps.length > 1 ? eps[eps.length - 1].code : null;
-        const sig = softSignature(depDate(row.reservation_time), meta.flight_number ?? null, from, to);
+        const sig = softSignature(depDate(row.reservation_time), (meta.flight_number as string | null | undefined) ?? null, from, to);
         if (sig) existingSigs.add(sig);
       }
     }

server/src/nest/integrations/airtrail-link.service.ts

@@ -16,6 +16,8 @@ import { AirtrailClient } from './airtrail.client';
 import { AirtrailService } from './airtrail.service';
 import { canonicalHash } from './airtrail.mapper';
 import { buildSavePayload } from './airtrail-sync.helpers';
+import { RESERVATION_METADATA } from '../../db/json-columns';
+import { decodeJson } from '../../utils/json-column';
 
 /**
  * The AirTrail link lifecycle — the enablement gate, the detach policy, the
@@ -70,12 +72,9 @@ export class AirtrailLinkService {
    * AirTrail flight to span the whole route (#1535).
    */
   async hasLocalMultiLegShape(reservationId: number, metadataJson: string | null | undefined): Promise<boolean> {
-    try {
-      const meta = metadataJson ? JSON.parse(metadataJson) : {};
-      if (Array.isArray(meta?.legs) && meta.legs.length > 1) return true;
-    } catch {
-      /* malformed metadata — fall through to the endpoint count */
-    }
+    // Malformed metadata falls through to the endpoint count.
+    const legs = decodeJson(RESERVATION_METADATA, metadataJson, `reservation ${reservationId}`).legs;
+    if (Array.isArray(legs) && legs.length > 1) return true;
     const n = await this.endpointsRepo.count({ reservation: reservationId });
     return n > 2;
   }

server/src/nest/integrations/airtrail-sync.helpers.ts

@@ -1,6 +1,8 @@
 import { entityCode } from './airtrail.mapper';
 import { flightPassengers, ownPassenger } from './airtrail.client';
 import type { AirtrailFlightRaw, AirtrailPassengerWrite, AirtrailSavePayload } from './airtrail.client';
+import { RESERVATION_METADATA } from '../../db/json-columns';
+import { decodeJson } from '../../utils/json-column';
 
 /**
  * The pure half of the AirTrail push: turning a TREK reservation plus the flight
@@ -27,12 +29,7 @@ function splitLocal(dt: string | null | undefined): { date: string | null; time:
  * (#1240).
  */
 export function buildSavePayload(reservation: any, existing: AirtrailFlightRaw): AirtrailSavePayload | null {
-  let meta: Record<string, any>;
-  try {
-    meta = reservation.metadata ? JSON.parse(reservation.metadata) : {};
-  } catch {
-    meta = {};
-  }
+  const meta = decodeJson(RESERVATION_METADATA, reservation.metadata, `reservation ${reservation.id}`);
   const endpoints: any[] = reservation.endpoints || [];
   const fromEp = endpoints.find((e) => e.role === 'from');
   const toEp = endpoints.find((e) => e.role === 'to');