Replace batch DAG system with streaming architecture

- Remove legacy_tasks.py, hybrid_state.py, render.py
- Remove old task modules (analyze, execute, execute_sexp, orchestrate)
- Add streaming interpreter from test repo
- Add sexp_effects with primitives and video effects
- Add streaming Celery task with CID-based asset resolution
- Support both CID and friendly name references for assets
- Add .dockerignore to prevent local clones from conflicting

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

sexp_effects/effects/rotate.sexp

@@ -0,0 +1,11 @@
+;; Rotate effect - rotates image
+
+(require-primitives "geometry")
+
+(define-effect rotate
+  :params (
+    (angle :type int :default 0 :range [-360 360])
+    (speed :type int :default 0 :desc "rotation per second")
+  )
+  (let ((total-angle (+ angle (* speed t))))
+    (geometry:rotate-img frame total-angle)))