Mock — Playground

Spark Series — Submit Your Idea

Drop-in mock of the sparkseries action. Same fields, same upload kinds — but the upload pipeline returns a real success only when the file actually persists. No silent drops.

What this mock fixes: the live action's upload extracts the file's "extension" from the request Content-Type header rather than the filename, so anything sent as a verbose MIME (most Office docs) gets a token like document/presentation/sheet that fails validation — and the entry still completes silently with blank fields. The mock derives the extension from the filename first and refuses to mark the entry complete if the file rejected.

Mock for Spark Series upload investigation. Submissions are stored in playground KV with prefix sparkseries-test: for review only — they don't enter any prod system.