tech debt #277: remove entire credits system

[sonikro]

Summary

Implements issue #277 by removing the full credits system across core, providers, and entrypoints.

What was removed

Core

• Removed domain models:
  • CreditOrder
  • CreditOrderRequest
  • CreditsConfig
• Removed repositories:
  • CreditOrdersRepository
  • UserCreditsRepository
• Removed service:
  • PaymentService
• Removed use-cases (+ tests):
  • ConsumeCreditsFromRunningServers
  • CreateCreditsPurchaseOrder
  • HandleOrderPaid
  • TerminateServersWithoutCredit
• Updated CreateServerForUser to remove credits checks/dependencies.
• Updated ConfigManager to remove getCreditsConfig.
• Updated packages/core/index.ts and domain/index.ts exports.

Providers

• Removed repositories:
  • SQliteCreditOrdersRepository
  • SQliteUserCreditsRepository
• Removed services (+ tests):
  • AdyenPaymentService
  • PaypalPaymentService
  • PaypalPaymentServiceTypes
• Updated repository/index.ts and services/index.ts exports.
• Updated DefaultConfigManager to remove getCreditsConfig.
• Removed @adyen/api-library from packages/providers/package.json.

Entrypoints

• Removed command directories (+ tests):
  • commands/BuyCredits/
  • commands/GetBalance/
• Removed jobs (+ tests):
  • ConsumeCreditsRoutine
  • TerminateServersWithoutCreditRoutine
• Removed HTTP middleware files:
  • adyenMiddleware.ts
  • paypalMiddleware.ts
  • PayPalOrderApprovedWebhookPayload.ts
• Updated commands/index.ts, jobs/index.ts, and discordBot.ts wiring.
• Updated discordBot.test.ts and CreateServerForUser.test.ts to align with removal.

Migrations (append-only)

• Added migrations/20260528224500_drop_user_credits.ts
• Added migrations/20260528224600_drop_credit_orders.ts

Config

• Removed credits section from config/default.json.

Validation

• Updated lockfile with npm install --package-lock-only.
• Performed symbol scans confirming no tracked source references remain for removed credits types/services/use-cases.

Notes

• Full build/test execution is currently blocked in this runner by npm workspace symlink/UNC path issues (EISDIR during install / script execution), not by project code errors.

Closes #277