feat: ( payment ) create payment microservice

CLAUDE.md

@@ -12,6 +12,7 @@ Monorepo for the Ethio Djibouti Railway (EDR) digital platform. Contains the Fre
 | `edr-freight-web/portal`       | `@edr/freight-portal`       | React frontend for freight customer/portal users   | 5173 |
 | `edr-freight-web/backoffice`   | `@edr/freight-backoffice`   | React frontend for freight backoffice employees    | 5183 |
 | `edr-passenger-api`            | `@edr/passenger-api`        | NestJS API for passenger management                | 3002 |
+| `edr-payment-api`              | `@edr/payment-api`          | NestJS payment microservice (intents, webhooks)    | 3003 |
 | `edr-passenger-web/portal`     | `@edr/passenger-portal`     | React frontend for passenger customer/portal users | 5174 |
 | `edr-passenger-web/backoffice` | `@edr/passenger-backoffice` | React frontend for passenger backoffice employees  | 5184 |
 
@@ -73,6 +74,7 @@ The `@CurrentUser`, `@Roles`, and `@Public` decorators in `@edr/api-common` are
 - `edr-freight-web/portal`: 5173
 - `edr-freight-web/backoffice`: 5183
 - `edr-passenger-api`: 3002
+- `edr-payment-api`: 3003
 - `edr-passenger-web/portal`: 5174
 - `edr-passenger-web/backoffice`: 5184
 
@@ -80,6 +82,7 @@ The `@CurrentUser`, `@Roles`, and `@Public` decorators in `@edr/api-common` are
 
 - `postgres-freight` (port 5433): database `edr_freight` — freight API only.
 - `postgres-passenger` (port 5434): database `edr_passenger` — passenger API only.
+- `edr_payment` schema — lives in the same Postgres database as the domain system (whatever the passenger `DATABASE_URL` points at) but is owned exclusively by `apps/edr-payment-api`. Dedicated DB user, no cross-schema FKs, domain apps have no grants on it (see `docs/payment-service/`).
 - Each app owns its own DB. No cross-database joins; cross-domain data flows through API calls or message queues.
 
 ## Adding a new module to a NestJS app