b6461e20

By: Michael Lynch <git@mtlynch.io>

Decouple media deletion tests from handlers

Expose a media-layer not-found error so deletion handlers no longer depend on
the SQLite store contract. Keep file-deletion and recovery behavior in media
service tests, and restore HTTP coverage for malformed and unknown media IDs.
configuredevShellx86_64-linuxbackendbackend-devcheck-bashcheck-frontendcheck-go-formattingcheck-go-test-packagescheck-trailing-newlinecheck-trailing-whitespacedeploy-to-flydiagramdocker-imagee2e-testsgo-testsimport-from-tinybeansjs-testslint-sqllittle-momentslittle-moments-devx86_64-linux