Refactor code structure and dependencies

- Remove unused files and modules
- Update submodule URL for epess-database
- Update DATABASE_URL in compose.yaml
- Update CI workflow to fetch submodules during checkout and fix GITHUB_TOKEN issue
- Enable strict mode in tsconfig.json
- Add UsersService and UsersResolver in users module
- Remove AppService and AppController
- Update main.ts to remove unused imports and log statement
- Add PrismaModule and PrismaService
- Add PrismaContextMiddleware
- Update GraphQL module to use schema and PrismaService
- Update package.json dependencies and devDependencies

src/prisma/prisma.module.ts

@@ -1,9 +1,8 @@
-import { Global, Module } from '@nestjs/common';
+import { Module } from '@nestjs/common';
 import { PrismaService } from './prisma.service';
 
-@Global()
 @Module({
   providers: [PrismaService],
-  exports: [PrismaService],
+  exports: [PrismaService], // Export PrismaService so other modules can use it
 })
 export class PrismaModule {}

src/prisma/prisma.service.ts

@@ -2,10 +2,7 @@ import { Injectable, OnModuleInit, OnModuleDestroy } from '@nestjs/common';
 import { PrismaClient } from '@prisma/client';
 
 @Injectable()
-export class PrismaService
-  extends PrismaClient
-  implements OnModuleInit, OnModuleDestroy
-{
+export class PrismaService extends PrismaClient implements OnModuleInit, OnModuleDestroy {
   async onModuleInit() {
     await this.$connect();
   }