Rewrite file/path handling to use std::filesystem and UTF-8-safe helpers.
Switch Windows file open/create paths to wide-char APIs, replace manual
separator concatenation with PathJoin, and enable RocksDB UTF-8 filenames.
Also add UTF-8 path coverage for file IO, version manager recovery, and
collection open/flush/reopen flows.
* support ios build
* fix: ci
* fix: update build_ios.sh
* fix: pr
* fix: cmake minimum version
* fix: cmake minimum version
* fix: cmake minimum version in ci
* fix: add all test in ci
* fix: ci