Adaptify.PureView 0.1.21

• • Aardvark.Build (>= 2.0.7 && < 2.1.0)
  • FSharp.Core (= 8.0.403)
  • FSharp.Data.Adaptive (>= 1.2.26 && < 1.3.0)

- fix: a builder-attribute sink fed a LIFTED value — e.g. `Sg.VertexAttribute("Colors", colors)` where `colors` is a let-bound derived value, or any multi-argument sink with one adaptive arg — now binds the sink's `aval<_>` overload directly instead of over-lifting the whole call to an unyieldable `aval<SceneAttribute>`. The 0.1.20 consumer-pull-out (single-arg) is generalized to multi-arg sinks and `aval<'a[]>`-shaped overloads; an identity pulled-out `AVal.map` collapses to the bare cell.
- feat: a CE-item `if … then … else …` whose branches yield the SAME attributes differing only in VALUE collapses to static attributes with each differing slot hoisted to one conditional `aval` over the discriminator (a shared tuple lift for ≥2 slots) — sink-agnostic (the differ-vs-same arg split is the key/value split).
- feat: invariant — the generator NEVER emits `aval<SceneAttribute>`. When scene structure is genuinely adaptive (an attribute exists in one branch but not another, or a `match` on a lifted discriminator), it lifts the WHOLE node to `aval<ISceneNode>` (which the builder yields) — coarse (rebuilds on the discriminator change), always valid, with a warning pointing to the fine-grained static-attribute/adaptive-value helper. It refuses only when the builder has no `aval<node>` Yield at all.
- (deferred) fine-grained per-arm value-hoist for a 3+-arm `match` — those still lower, via the coarse whole-node fallback.