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>

templates/standard-effects.sexp

@@ -0,0 +1,22 @@
+;; Standard Effects Bundle
+;;
+;; Loads commonly-used video effects.
+;; Include after primitives are loaded.
+;;
+;; Effects provided:
+;;   - rotate: rotation by angle
+;;   - zoom: scale in/out
+;;   - blend: alpha blend two frames
+;;   - ripple: water ripple distortion
+;;   - invert: color inversion
+;;   - hue_shift: hue rotation
+;;
+;; Usage:
+;;   (include :path "../templates/standard-effects.sexp")
+
+(effect rotate :path "../sexp_effects/effects/rotate.sexp")
+(effect zoom :path "../sexp_effects/effects/zoom.sexp")
+(effect blend :path "../sexp_effects/effects/blend.sexp")
+(effect ripple :path "../sexp_effects/effects/ripple.sexp")
+(effect invert :path "../sexp_effects/effects/invert.sexp")
+(effect hue_shift :path "../sexp_effects/effects/hue_shift.sexp")