Newer Claude models reject a body that ends on an assistant turn. The
empty-message cleanups in prepareClaudeRequest and normalizeClaudePassthrough
protect a trailing assistant but not a trailing user turn, so an emptied last
user turn silently made the previous assistant turn the last one.
ensureTrailingUserTurn appends a minimal user turn ("Continue.") only when the
client did not itself end on assistant, in both cleanup paths and in
translateRequest against the role the client actually sent.
Amirsalar Sojoudi
75834e96ff