Render continuously and optimize the glTF viewer

Remove vsync and dirty-flag frame gating, optimize PBR sampling and lighting, add a direct-to-canvas loadout, and preserve camera state on viewer resize.

Add regression coverage and update rendering documentation.

Amp-Thread-ID: https://ampcode.com/threads/T-01a0b382-1e79-712b-abd1-d29201c9bb5e
Co-authored-by: Heaust Azure <heaust.azure@gmail.com>

core/lib.rs

@@ -161,7 +161,6 @@ impl Core {
         if names.iter().any(|name| self.store.borrow().uses_rows(name)) {
             self.refresh()?;
         }
-        self.data.borrow_mut().mark_dirty();
         Ok(())
     }
 
@@ -219,7 +218,6 @@ impl Core {
             .borrow_mut()
             .delete_object(name, id)
             .map_err(JsError::new)?;
-        self.data.borrow_mut().mark_dirty();
         Ok(())
     }
 
@@ -233,7 +231,6 @@ impl Core {
             .borrow()
             .sync_rows(name, first, count, gpu, &self.data.borrow())
             .map_err(|error| JsError::new(&error))?;
-        self.data.borrow_mut().mark_dirty();
         Ok(())
     }
 
@@ -269,7 +266,6 @@ impl Core {
             .borrow_mut()
             .upload_texture(name, mip_level, image, gpu)
             .map_err(|error| JsError::new(&error))?;
-        self.data.borrow_mut().mark_dirty();
         Ok(())
     }
 
@@ -296,9 +292,6 @@ impl Core {
             .as_ref()
             .is_some_and(|gpu| gpu.timestamp_queries);
         self.render.set_profiling(enabled && supported);
-        if enabled && supported {
-            self.data.borrow_mut().mark_dirty();
-        }
         supported
     }