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/resize-frame.sexp

@@ -1,5 +1,6 @@
 ;; Resize effect - replaces RESIZE node
 ;; Note: uses target-w/target-h to avoid conflict with width/height primitives
+(require-primitives "image")
 
 (define-effect resize-frame
   :params (
@@ -7,4 +8,4 @@
     (target-h :type int :default 480 :desc "Target height in pixels")
     (mode :type string :default "linear" :choices [linear nearest area] :desc "Interpolation mode")
   )
-  (resize frame target-w target-h mode))
+  (image:resize frame target-w target-h mode))