Upstream /destinations and /days endpoints expect yyyy-MM-DD (dashed),
matching Angular's ApiFormatterService.formatDateOnly output. React was
sending the internal compact yyyyMMdd, triggering silent 400s.
Also fix dev-server.mjs status-code parsing: empty-body curl responses
start with the appended "\n%{http_code}" separator at index 0, so
`lastNewline > 0` mis-treated the status as body and defaulted to 200,
hiding real upstream 4xx/5xx responses. Changed to `>= 0`.
gnezim
5551cb1821