CORS: drop allow_credentials=True. With allow_origins=['*'] Starlette reflects
the request Origin and emits Access-Control-Allow-Credentials: true on any
credentialed request — a reflect-any-origin hole. The app authenticates with
Bearer tokens in the Authorization header, so credentialed CORS was never needed.
/icons/{icon_name}: validate against a strict allowlist (re.fullmatch
[A-Za-z0-9._-]+\.png) and assert the resolved path stays inside ICONS_DIR before
any filesystem write or outbound fetch. Closes the path-traversal / arbitrary-write
(CWE-22) and controlled-URL (CWE-73) surface on the unsanitized icon_name.
Adds CORS middleware tests and icon-name validation tests (traversal, encoded
slash, null byte, trailing newline, wrong extension).
Closes#298
Signed-off-by: Devam Shah <devamshah91@gmail.com>
