bcrypt with a fixed salt is deterministic but defeats the purpose of
bcrypt salting. API keys are high-entropy UUIDs (128 bits), making
brute-force resistance unnecessary — HMAC-SHA256 with the app secret
is the correct primitive for deterministic, secure key hashing.
Also fixes application.author.id → application.authorId in the API key
auth path, which was silently setting req.payload.id to undefined.
julien