Review round 1 on PR #175: - entryIndex returned WalkRegular's walk-root ErrNotRegular as an error, and StripUnresolvedLinks runs before every brain_write: a symlinked, dangling or regular-file knowledge/ (or wiki/) made every write fail and lose the learning. main's filepath.WalkDir skipped such a root. It is now skipped with a warning; other walk errors still abort, as on main. New table test over the three shapes. - The symlinked-hall assertion passed with no index written at all. It now indexes a real hall next to the symlinked one and asserts no error, the index exists and lists the real note; a new test does the same for BuildAllWingIndexes with a symlinked wing next to a real one. - The test comment no longer says this PR fixed the FIFO hang on every brain_write: that path is tunnel.DetectTunnels (slice 5b). Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>