file-upload

One multipart endpoint enforces four contracts: closed enums, conditional file slots, bounded streaming, and safe schema migration.

TL;DR: The upload form enforces four contracts: hand-maintained Go enums for validation, files that become required only when a flag says so, streaming writes capped at 10 MiB with magic-byte checks into private storage, and schema migrations that clean up enum values before narrowing on rollback. All four must stay synchronized server-side. Any drift breaks the endpoint predictably.