env.BUCKET.get(key, { range: request.headers }) makes R2 report a
DEFINED object.range (full span) even when the request carried no Range
header, so every plain GET went out as 206 + Content-Range. Chrome
executes a 206 <script>; Firefox fires onload but refuses to EXECUTE
the script — on hosts with no masking edge cache (staging workers.dev)
the injected editor glue never ran: no [KICAD_STATUS] logs, heap 0MB,
'runtime did not initialize (no FS) in 90s' on every Firefox boot.
Prod's cdn.pcbjam.com zone cache normalizes cached hits to 200, which
is why only staging surfaced it; cold prod objects share the bug.
Pass the range option only when the request actually sent a Range.
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01PmR6goSk7JC17h7fkgGvHG
42479b313c