feat: add siegetank unit set and implement messaging system

- Created a new unit set for "siegetank" with various crew types and their attributes.
- Implemented a messaging system with types, payloads, and storage functionality.
- Added tests for the messaging system to ensure correct behavior for different message types (private, national, public, diplomacy).

app/game-api/src/context.ts

@@ -1,4 +1,5 @@
 import type { GameSessionTokenPayload } from '@sammo-ts/common';
+import type { Prisma } from '@prisma/client';
 
 import type { TurnDaemonTransport } from './daemon/transport.js';
 
@@ -100,6 +101,7 @@ export interface NationRow {
 }
 
 export interface DatabaseClient {
+    $queryRaw<T = unknown>(query: Prisma.Sql): Promise<T>;
     worldState: {
         findFirst(args?: unknown): Promise<WorldStateRow | null>;
     };