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/brightness.sexp

@@ -1,10 +1,9 @@
 ;; Brightness effect - adjusts overall brightness
 ;; Uses vectorized adjust primitive for fast processing
-
 (require-primitives "color_ops")
 
 (define-effect brightness
   :params (
     (amount :type int :default 0 :range [-255 255])
   )
-  (adjust frame amount 1))
+  (color_ops:adjust-brightness frame amount))