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/test/configs/audio-dizzy.sexp

@@ -0,0 +1,17 @@
+;; Audio Configuration - dizzy.mp3
+;;
+;; Defines audio analyzer and playback for a recipe.
+;; Pass to recipe with: --audio configs/audio-dizzy.sexp
+;;
+;; Provides:
+;;   - music: audio analyzer for beat/energy detection
+;;   - audio-playback: path for synchronized playback
+
+(require-primitives "streaming")
+
+;; Audio analyzer (provides beat detection and energy levels)
+;; Paths relative to working directory (project root)
+(def music (streaming:make-audio-analyzer "dizzy.mp3"))
+
+;; Audio playback path (for sync with video output)
+(audio-playback "dizzy.mp3")