Stage 5: Add Prisma integration and enhance mission management

- Introduced Prisma as a dependency in package.json and updated pnpm-lock.yaml.
- Created Prisma module and service for database interactions.
- Added initial Prisma schema and migration for user, survivor, mission, and related entities.
- Implemented throttling in the API using @nestjs/throttler for rate limiting.
- Enhanced mission management logic to utilize Prisma for database transactions.
- Updated missions controller and service to handle mission state and participant management.
- Added Twitch PubSub service for real-time updates on mission states.

.claude/settings.json

@@ -2,6 +2,7 @@
   "permissions": {
     "allow": [
       "Bash(node -e *)",
+      "Bash(python3 *)",
       "Bash(node --input-type=module)",
       "Bash(2>&1)",
       "Bash(pnpm *)"