README.md: the opening no longer says the private key is needed only to
restore; a backup never needs it, a deep verify does.
ARCHITECTURE.md: the concurrency note says each open database uses one
connection, since the metadata export opens a second one.
docs/REPOSTRUCTURE.md: the size leak is about a secret near the
outsider's data in the same blob, not the same chunk, because all new
chunks of a blob share one zstd stream.
Every path used as link text in the four documents is in backticks.
Model: fable-5-1
sneak
49af986fd1