Ensures that proper Content-Type headers are set on pass-through static files

Editor assessment

The subject identifies the exact behavior fixed: pass-through static files now receive correct Content-Type headers. That is meaningful to anyone serving uploads or proxies and requires no diff to understand. The fix type matches a correctness change, and the absent scope is acceptable because the mechanism is named inline. No body explains which headers were wrong or the user-visible consequence — a modest lost opportunity — but the change reads as contained and self-sufficient. Style is clean: imperative-adjacent, no trailing period, no ticket junk, no footers required. Good and publishable.