Add generic streaming interpreter with configurable sources/audio

- Add stream_sexp_generic.py: fully generic sexp interpreter
- Add streaming primitives for video sources and audio analysis
- Add config system for external sources and audio files
- Add templates for reusable scans and macros
- Fix video/audio stream mapping in file output
- Add dynamic source cycling based on sources array length
- Remove old Python effect files (migrated to sexp)
- Update sexp effects to use namespaced primitives

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

sexp_effects/effects/blur.sexp

@@ -1,9 +1,8 @@
 ;; Blur effect - gaussian blur
-
-(require-primitives "filters" "math")
+(require-primitives "image")
 
 (define-effect blur
   :params (
     (radius :type int :default 5 :range [1 50])
   )
-  (blur frame (max 1 radius)))
+  (image:blur frame (max 1 radius)))