The token is the entire access control on an endpoint the whole internet can reach, so both halves are pure and tested directly rather than through a request — the same reasoning that has uploadTypes.ts and keyByCallerAndEmail exported for their tests.
32 bytes of CSPRNG output, base64url so the value survives being pasted into a URL, a chat message or a QR code without escaping. That matters for something a person is handed rather than something a machine reads. The collision test runs a thousand generations rather than asserting the obvious, because a repeat would mean one person's link opening another's.
SHA-256 rather than bcrypt, and the reasoning inverts the one that governs passwords. A password hash is slow on purpose because a human password carries little entropy and must survive an offline dictionary attack. This is 256 bits from a CSPRNG: there is no dictionary, so slowing the hash buys nothing. Meanwhile the digest is computed on every submission to an unauthenticated endpoint, where a deliberately slow hash would be a denial-of-service surface — #242 is the local proof that cost-12 hashing on a request path is enough to push it past a timeout under load.
No timing-safe comparison, deliberately: the lookup is an indexed equality match on the digest rather than a byte-by-byte compare of the secret, and an attacker who could mount a timing attack against a 256-bit random value would still need the value.
Backend: 307 unit tests, lint unchanged at 6 pre-existing warnings, build clean.
Ref #222
