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/bloom.sexp

@@ -0,0 +1,16 @@
+;; Bloom effect - glow on bright areas
+(require-primitives "image" "blending")
+
+(define-effect bloom
+  :params (
+    (intensity :type float :default 0.5 :range [0 2])
+    (threshold :type int :default 200 :range [0 255])
+    (radius :type int :default 15 :range [1 50])
+  )
+  (let* ((bright (map-pixels frame
+                   (lambda (x y c)
+                     (if (> (luminance c) threshold)
+                         c
+                         (rgb 0 0 0)))))
+         (blurred (image:blur bright radius)))
+    (blending:blend-mode frame blurred "add")))