CVE-2026-55614: uhttpd vulnerable to HTTP request smuggling via case-sensitive Transfer-Encoding matching

uhttpd is a small HTTP server. In unpatched repository snapshots, clientparseheader() in client.c lowercases header names but compares the Transfer-Encoding value to chunked using case-sensitive strcmp. A mixed-case transfer-coding token is accepted without enabling r->transferchunked, despite transfer-coding tokens being case-insensitive. On a keep-alive connection, the chunked POST body is left unread and request-shaped body bytes are parsed as another HTTP request, permitting HTTP request smuggling and boundary desynchronization. Commits ae015e099986ceace44975cb69629841a2d58d37 and 6641b050e5f7c7fd9ae92e8e119d6d6dfc6e9837 patch the issue.