Verify each finding against current code. Fix only still-valid issues, skip the
rest with a brief reason, keep changes minimal, and validate.

Inline comments:
In `@server/api/registry/image-proxy/index.get.ts`:
- Around line 159-164: The extension check in
server/api/registry/image-proxy/index.get.ts is case-sensitive and blocks valid
image URLs like .PNG/.JpG; update the validation in the image-proxy GET handler
(the block that uses endsWith against the extensions array) to perform a
case-insensitive check by normalizing the URL/pathname or filename to lowercase
before calling endsWith (or replace endsWith checks with a case-insensitive
regex), ensuring the same allowed extensions list is used but comparisons ignore
case.
- Around line 157-166: The MIME comparison in the image proxy handler
(index.get) uses an exact match against "application/octet-stream", which misses
values with parameters like "application/octet-stream; charset=binary"; update
the logic that reads the response Content-Type (e.g., the variable holding the
MIME/type) to normalize it by lowercasing and splitting on ";" then trimming the
media type before doing the equality check and fallback decision; replace direct
comparisons to "application/octet-stream" with comparisons against this
normalizedMediaType so the fallback path triggers correctly.