Stream deferred visual nodes in camera-distance order (nearest first)

The progressive load previously streamed the deferred visual nodes (3d model
instances + terrain shapes/lines) in file order, so distant scenery could load
before the player's surroundings. This builds them nearest-camera first instead.

The visual pass now runs in two steps. Enumeration replays the twin and captures
each visual node verbatim (its resolved tokens as text -- numbers round-trip
losslessly through cParser) together with the transform/group context it was read
under and, for models, its transformed world position. Once the replay is
exhausted the records are sorted by squared distance to the camera (terrain shapes
first so the ground appears before the props on it), then built a budgeted slice
per frame through the normal node path with the captured transform and group
restored -- so placement, grouping and the per-cell instance buckets come out
identical to an in-order load.

Two supporting fixes make out-of-order/late insertion correct:
- a cell/section whose geometry was already baked (the renderer finalised it
  before a deferred node arrived) now appends the new shape/lines straight into
  its live geometry bank instead of merging into vertex-freed geometry, which
  would silently drop it; create_geometry() remembers the bank for every cell.
- events that bind to visual model instances (lights/animation/texture/visible)
  are deferred from InitEvents() to a new InitInstanceEvents() run after the
  visual nodes are built, so their target models exist when they initialise.

Verified on td.scn: playable ~2s, 540 deferred nodes enumerated and built
nearest-first ~0.5s later, no duplicate instances.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

scene/scene.cpp

@@ -275,6 +275,16 @@ basic_cell::insert( shape_node Shape ) {
         shapedata.translucent ?
             m_shapestranslucent :
             m_shapesopaque );
+    // if this cell's geometry was already baked (deferred visual streaming inserting into a
+    // section the renderer already finalised), don't try to merge into an existing shape
+    // whose CPU-side vertices were freed at bake time -- add the shape standalone and upload
+    // it straight into the live bank, otherwise it would never become visible.
+    if( m_geometrybank != null_handle ) {
+        Shape.origin( m_area.center );
+        shapes.emplace_back( Shape );
+        shapes.back().create_geometry( m_geometrybank );
+        return;
+    }
     for( auto &targetshape : shapes ) {
         // try to merge shapes with matching view ranges...
         auto const &targetshapedata { targetshape.data() };
@@ -302,6 +312,14 @@ basic_cell::insert( lines_node Lines ) {
     m_active = true;
 
     auto const &linesdata { Lines.data() };
+    // see the matching note in insert( shape_node ): once the cell is baked, append the new
+    // lines straight into the live bank rather than merging into vertex-freed geometry.
+    if( m_geometrybank != null_handle ) {
+        Lines.origin( m_area.center );
+        m_lines.emplace_back( Lines );
+        m_lines.back().create_geometry( m_geometrybank );
+        return;
+    }
     for( auto &targetlines : m_lines ) {
         // try to merge shapes with matching view ranges...
         auto const &targetlinesdata { targetlines.data() };
@@ -632,6 +650,10 @@ basic_cell::center( glm::dvec3 Center ) {
 void
 basic_cell::create_geometry( gfx::geometrybank_handle const &Bank ) {
 
+    // remember the bank for *all* cells (even ones empty at bake time): a deferred visual
+    // node may activate this cell later, and insert() needs the live bank to upload into.
+    m_geometrybank = Bank;
+
     if( false == m_active ) { return; } // nothing to do here
 
     for( auto &shape : m_shapesopaque )      { shape.create_geometry( Bank ); }
@@ -850,6 +872,14 @@ basic_section::insert( shape_node Shape ) {
     }
     else {
         // large, opaque shapes are placed on section level
+        // if the section was already baked (deferred visual streaming), append straight into
+        // the live bank instead of merging into vertex-freed geometry -- see basic_cell::insert.
+        if( true == m_geometrycreated ) {
+            Shape.origin( m_area.center );
+            m_shapes.emplace_back( Shape );
+            m_shapes.back().create_geometry( m_geometrybank );
+            return;
+        }
         for( auto &shape : m_shapes ) {
             // check first if the shape can't be merged with one of the shapes already present in the section
             if( true == shape.merge( Shape ) ) {