feat: add render graph driven renderer architecture

Amp-Thread-ID: https://ampcode.com/threads/T-019f9d91-77c1-7206-a60f-ed6554ce92ab

Co-authored-by: Heaust Azure <heaust.azure@gmail.com>

vendor/fxnode/docs/index.md

@@ -0,0 +1,31 @@
+---
+layout: home
+
+hero:
+  name: fxnode
+  text: A worker-owned node editor
+  tagline: Compose a typed graph language, present it on Canvas, and persist it safely.
+  actions:
+    - theme: brand
+      text: Start learning
+      link: /learn/
+    - theme: alt
+      text: API Reference
+      link: /reference/
+
+features:
+  - title: Worker authority
+    details: Commands, validation, hit testing, layout, history, and rendering live behind one explicit boundary.
+  - title: Zero or many views
+    details: Run headlessly or attach independent canvases with view-local cameras, selections, input, and rendering to one shared graph.
+  - title: Application composition
+    details: Your application supplies node definitions, socket compatibility, theme, and resource policies.
+  - title: Durable documents
+    details: Canonical saves, bounded decoding, opaque unknown nodes, and declarative migrations protect user data.
+---
+
+::: warning Prerelease
+fxnode is an internal `0.x` prerelease. APIs and persistence contracts can still change.
+:::
+
+fxnode **presents and persists** node graphs. It does not evaluate or execute them. It is not Blender-compatible and makes no Blender feature or visual parity claim.