backfillSearchMeta

Re-derive the search .metadata for existing assets whose type records facet data there — a bundle's component set and humanoid classification, an animation's humanoid classification.

New and edited assets get this from their type's onChange hook. Assets with no recorded .metadata.components / .metadata.humanoid have search facets that read a false negative (an unrecorded asset looks the same as one that genuinely lacks the trait). Run this to populate them.

tools.use("assets", "backfillSearchMeta", {})            -- bundle + animation
tools.use("assets", "backfillSearchMeta", { types = { "bundle" } })

Idempotent: re-running recomputes the same values. Only assets whose type exposes a reindexSearchMeta ref method are touched; everything else is counted as scanned and left alone. Returns { total, byType = { <type> = { scanned, reindexed } } }.