isModelAllowedForKey() existed in src/lib/db/apiKeys.ts but was never
called anywhere. API keys with allowedModels restrictions could access
any model through any endpoint.
Changes:
- Add shared enforceApiKeyPolicy() middleware (model restriction + budget)
- Wire it into chat handler (replacing inline budget-only check)
- Wire it into all /v1/* endpoints: embeddings, images/generations,
audio/speech, audio/transcriptions, moderations, rerank
- Wire it into provider-specific endpoints: /v1/providers/[provider]/embeddings,
/v1/providers/[provider]/images/generations
The middleware checks:
1. Model restriction — if key has allowedModels, verify the model is permitted
2. Budget limit — if key has budget configured, verify it hasn't been exceeded
Fixes#130
0c0a56d4de