fix: keep exact snapping, source drawing data and adaptive options layout

Resolve curve intersections through cadkernel, retain empty exact results, gather analytic candidates independently of tessellation, and bound material uploads. Preserve large MINSERT data while limiting rendering work; remove obsolete review narratives.

src/scene/mod.rs

@@ -1877,12 +1877,6 @@ pub struct Scene {
     entity_block_map_cache: RefCell<Option<(u64, HashMap<Handle, Handle>)>>,
     /// Candidate handles per block, in document order and keyed by geometry epoch.
     block_members_cache: RefCell<Option<BlockMembers>>,
-    /// Annotation handle -> the LEADERs that point at it, resolved once per
-    /// `geometry_epoch`.
-    ///
-    /// Selecting an entity has to pull in a LEADER whose annotation it is, and
-    /// that used to be answered by walking the whole document — per selected
-    /// handle. Selecting N entities cost N document walks.
     leaders_by_annotation_cache: RefCell<Option<(u64, HashMap<Handle, Vec<Handle>>)>>,
     /// Insert/Viewport/Block/BlockEnd handles omitted by the spatial index.
     unindexable_cache: RefCell<Option<(u64, Vec<Handle>)>>,
@@ -7865,12 +7859,6 @@ impl Scene {
         (Arc::new(wires), base_slots, changed_slots)
     }
 
-    /// `area_only` skips the snap-only categories and gathers the rest without
-    /// sorting; see [`InteractionIndex::query_xy_area`]. Both the overlay path
-    /// and the plain indexed path honour it — the overlay runs whenever the
-    /// drawing has been edited since the index was built, which is most of a
-    /// working session, so a saving that stopped there would stop the first
-    /// time the user drew something.
     fn indexed_interaction_candidates_xy(
         &self,
         wires: Arc<Vec<WireModel>>,