ensure tidy Close() with immutable=1

fix flaky test

since elimination of seek lock, reader threads need to lock zstd dict cache

Temporarily disable flaky test

Revamp logging for controllability with SQLITE_VFS_LOG or &vfs=log

simplify concurrency by enabling outer db mutex

Update README.md

Update README.md

remove unnecessary unix header includes

bump dependencies

bump web_vfs

bump web_vfs

bump SQLiteCpp

tidy vestigial variable

pageno filter for btree interior index