registerFileRoute
Register an additional route that serves a single file from disk. Reads the current publication on every request so subsequent atomic replacements are picked up immediately. Responses carry a strong SHA-1 ETag. IMS remains as a compatibility fallback when a caller does not send If-None-Match.
If the file does not exist when the request arrives, the route returns 404 with no body. This is intentional: it lets callers wire the route up before the producing step (e.g. BedrockConversion) has run, with the route starting to 200 the moment the file lands.
Parameters
the request path (e.g. BEDROCK_PACK_PATH). Must start with /.
the file to serve. Read per-request; may be missing.
the value of the Content-Type response header on 200 responses.
Register a dynamic route whose publisher can provide its existing SHA-1.