Fixed hidden comments collapsing threaded replies (#28123)

ref https://linear.app/ghost/issue/BER-3677/hidden-comments-collapse-thread-nesting-incorrectly

Comment APIs need to return hidden/deleted tombstones when they preserve the path to visible descendants. This uses a post-scoped path-based recursive SQL query for displayable comment IDs, keeps reply counts tied to visible comments, preserves local deleted reply tombstones while descendants are loaded, and bumps Comments UI for release.