fix(analyze): deduplicate hardlinked files so sizes match du (#906)

The recursive analyze scanner counted every directory entry, so a tree
with many hardlinks to the same inode (Final Cut Pro managed media in a
.fcpbundle) was counted once per link, over-reporting size 20-50x while
`du -skPx` reported it correctly.

Track (device, inode) of files with nlink > 1 in a scan-wide set on
scanLimiter and count each inode once, matching du. A subtree whose
size depended on dedup is marked non-cacheable so a standalone re-scan
is not poisoned. Bump the cache schema to v2 to discard stale entries
written before this change.