Root cause #1: BrowserMultiFormatReader constructor takes 0 args so hints
and timing options (passed as args) were silently ignored. Hints are now
applied as reader.reader.hints, and timing as instance properties.
Root cause #2: ZXing per-frame 'no barcode' exceptions have message=undefined
causing .toLowerCase() to crash in old message-text filter. Switched to
instanceof checks against NotFoundException, ChecksumException, FormatException
which properly distinguishes normal 'no barcode' frames from real errors.
Tested in browser — hint setting and error filtering both verified working.
shawn
3859d9d555