Incorporate art-dag-mono repo into artdag/ subfolder

Merges full history from art-dag/mono.git into the monorepo
under the artdag/ directory. Contains: core (DAG engine),
l1 (Celery rendering server), l2 (ActivityPub registry),
common (shared templates/middleware), client (CLI), test (e2e).

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

git-subtree-dir: artdag
git-subtree-mainline: 1a179de547
git-subtree-split: 4c2e716558

artdag/l1/test_heavy_fused.sexp

@@ -0,0 +1,39 @@
+;; Heavy Fused Pipeline Test
+;;
+;; Tests with many effects to show the full benefit of kernel fusion
+
+(stream "heavy_fused_test"
+  :fps 30
+  :width 1920
+  :height 1080
+  :seed 42
+
+  ;; Load primitives
+  (require-primitives "streaming_gpu")
+  (require-primitives "image")
+  (require-primitives "math")
+
+  ;; Define heavy effects pipeline (4 effects fused into one kernel)
+  (def heavy-pipeline
+    [{:op "rotate" :angle 0}
+     {:op "hue_shift" :degrees 30}
+     {:op "ripple" :amplitude 15 :frequency 10 :decay 2 :phase 0 :center_x 960 :center_y 540}
+     {:op "brightness" :factor 1.0}])
+
+  ;; Frame pipeline
+  (frame
+    (let [;; Create base image
+          r (+ 0.5 (* 0.5 (math:sin (* t 1))))
+          g (+ 0.5 (* 0.5 (math:sin (* t 1.3))))
+          b (+ 0.5 (* 0.5 (math:sin (* t 1.7))))
+          color [(* r 255) (* g 255) (* b 255)]
+          base (image:make-image 1920 1080 color)
+
+          ;; Dynamic parameters
+          angle (* t 30)
+          phase (* t 2)]
+
+      ;; 4 effects in ONE kernel call!
+      (streaming_gpu:fused-pipeline base heavy-pipeline
+        :rotate_angle angle
+        :ripple_phase phase))))