An unprefixed cookie blob is legacy data stored in the clear, and Chromium's
OSCrypt returns it as-is on both macOS and Linux (os_crypt_mac.mm and
os_crypt_linux.cc alike: "old data saved as clear text"). The reader only
honoured that on macOS, so a Linux import counted those rows as undecryptable
and dropped otherwise readable cookies. The fallback now applies on Linux as
well; Windows stays excluded, since its app-bound blobs also lack the prefix.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>