Render only when shared state changes

Add shared-data and bundle invalidation signals, and have handles publish them automatically for SAB and graph mutations.

Document the raw core worker protocol in a dedicated VitePress site and simplify the glTF import and picking example.

Amp-Thread-ID: https://ampcode.com/threads/T-01a01ff8-b91f-724f-8952-f07c6b5042fd
Co-authored-by: Heaust Azure <heaust.azure@gmail.com>

core/render_data_tests.rs

@@ -0,0 +1,32 @@
+use super::RenderData;
+
+#[test]
+fn dirty_signal_is_consumed_once() {
+    let mut data = RenderData::new(64).unwrap();
+
+    assert!(data.rows("signals").is_some());
+    assert!(data.begin_render());
+    assert!(!data.begin_render());
+
+    data.mark_dirty();
+    assert!(data.begin_render());
+    assert!(!data.render_pending());
+}
+
+#[test]
+fn skip_and_bundle_signals_hold_dirty_work() {
+    let mut data = RenderData::new(64).unwrap();
+    assert!(data.begin_render());
+
+    data.write_signal(4, 1.0);
+    data.mark_dirty();
+    assert!(!data.begin_render());
+    data.write_signal(4, 0.0);
+    assert!(data.begin_render());
+
+    data.write_signal(6, 1.0);
+    data.mark_dirty();
+    assert!(!data.begin_render());
+    data.loadout_ready();
+    assert!(data.begin_render());
+}