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/UPSTREAM.md

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+# fxnode upstream provenance
+
+- Source: https://github.com/Heaust-ops/fxnode
+- Commit: `3f8745717bf4574577be72e9769373475cc300c9`
+- Tree: `fb8bf407854b68dad8c0249c9ba63c7fd0bd9332`
+- Imported: 2026-07-26
+- License: MIT (see `LICENSE` and `NOTICE.md`)
+- Local patches: none
+
+This directory is a committed source snapshot. Application adaptations belong outside
+`vendor/fxnode`; do not modify vendored source for integration convenience.
+
+## Reimport
+
+```sh
+git clone --filter=blob:none https://github.com/Heaust-ops/fxnode /tmp/fxnode
+git -C /tmp/fxnode fetch --depth=1 origin 3f8745717bf4574577be72e9769373475cc300c9
+git -C /tmp/fxnode checkout --detach 3f8745717bf4574577be72e9769373475cc300c9
+rm -rf vendor/fxnode
+mkdir -p vendor/fxnode
+git -C /tmp/fxnode archive HEAD | tar -x -C vendor/fxnode
+```
+
+After importing, restore this file with the new commit/tree hashes and document any
+unavoidable local patches explicitly.