Hardening pass ahead of real client testing: unmatched routes and
unsupported methods now return a logged, JSON 404 instead of chi's
default plain-text response, so a missing endpoint a client needs is
easy to spot in the logs. Internal errors (ffmpeg output, file paths,
etc.) no longer leak into 500 response bodies -- a shared
internalError helper logs the real error server-side and always
returns a generic message. Inbound Jellyfin ratings are clamped to
0-10 before being halved into Navidrome's 0-5 scale, and /System/Ping
now replies with a bare plain-text body as real Jellyfin servers do.
Adds a README with an enable/curl walkthrough and known limitations.
Add jellyfin.New to the shared Wire provider set and a
CreateJellyfinAPIRouter injector, then mount the router at /jellyfin
in startServer(), gated by conf.Server.Jellyfin.Enabled, mirroring the
existing LastFM/ListenBrainz router mounts.
