perf(scene): cache block defns + batch wires by style

Tessellates each block_record once into local-coord LocalWires; Insert
references transform-copy + ByBlock-resolve the cache rather than
explode+re-tessellate per reference. Same-style wires inside one Insert
are NaN-batched into a single WireModel to keep wgpu buffer counts
sane — large blocks that previously bailed to a marker now render in
a handful of buffers each.

Co-Authored-By: Claude Opus 4.7 <[email protected]>

src/app/mod.rs

@@ -35,7 +35,7 @@ pub const OPEN_PHASE_CACHING: u8 = 2;
 pub const OPEN_PHASE_FINALIZING: u8 = 3;
 
 #[derive(Debug, Clone)]
-pub(super) struct OpenProgress {
+pub struct OpenProgress {
     pub name: String,
     pub size_bytes: u64,
     pub phase: Arc<AtomicU8>,