Add JAX typography, xector primitives, deferred effect chains, and GPU streaming

- Add JAX text rendering with font atlas, styled text placement, and typography primitives
- Add xector (element-wise/reduction) operations library and sexp effects
- Add deferred effect chain fusion for JIT-compiled effect pipelines
- Expand drawing primitives with font management, alignment, shadow, and outline
- Add interpreter support for function-style define and require
- Add GPU persistence mode and hardware decode support to streaming
- Add new sexp effects: cell_pattern, halftone, mosaic, and derived definitions
- Add path registry for asset resolution
- Add integration, primitives, and xector tests

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

sexp_effects/effects/xector_inset_blend.sexp

@@ -0,0 +1,57 @@
+;; Inset blend - fade a smaller frame into a larger background
+;; Uses distance-based alpha for smooth transition (no hard edges)
+
+(require-primitives "xector")
+
+(define-effect xector_inset_blend
+  :params (
+    (x :type int :default 0 :desc "X position of inset")
+    (y :type int :default 0 :desc "Y position of inset")
+    (fade-width :type int :default 50 :desc "Width of fade region in pixels")
+    (overlay :type frame :default nil :desc "The smaller frame to inset")
+  )
+  (let* (
+         ;; Get dimensions
+         (bg-h (first (list (nth (list (red frame)) 0))))  ;; TODO: need image:height
+         (bg-w bg-h)  ;; placeholder
+
+         ;; For now, create a simple centered circular blend
+         ;; Distance from center of overlay position
+         (cx (+ x (/ (- bg-w (* 2 x)) 2)))
+         (cy (+ y (/ (- bg-h (* 2 y)) 2)))
+
+         ;; Get coordinates as xectors
+         (px (x-coords frame))
+         (py (y-coords frame))
+
+         ;; Distance from center
+         (dx (α- px cx))
+         (dy (α- py cy))
+         (dist (αsqrt (α+ (α* dx dx) (α* dy dy))))
+
+         ;; Inner radius (fully overlay) and outer radius (fully background)
+         (inner-r (- (/ bg-w 2) x fade-width))
+         (outer-r (- (/ bg-w 2) x))
+
+         ;; Blend factor: 1.0 inside inner-r, 0.0 outside outer-r, linear between
+         (t (α/ (α- dist inner-r) fade-width))
+         (blend (α- 1 (αclamp t 0 1)))
+
+         ;; Extract channels from both frames
+         (bg-r (red frame))
+         (bg-g (green frame))
+         (bg-b (blue frame)))
+
+    ;; If overlay provided, blend it
+    (if overlay
+        (let* ((ov-r (red overlay))
+               (ov-g (green overlay))
+               (ov-b (blue overlay))
+               ;; Linear blend: result = bg * (1-blend) + overlay * blend
+               (r-out (α+ (α* bg-r (α- 1 blend)) (α* ov-r blend)))
+               (g-out (α+ (α* bg-g (α- 1 blend)) (α* ov-g blend)))
+               (b-out (α+ (α* bg-b (α- 1 blend)) (α* ov-b blend))))
+          (rgb r-out g-out b-out))
+        ;; No overlay - just show the blend mask for debugging
+        (let ((mask-vis (α* blend 255)))
+          (rgb mask-vis mask-vis mask-vis)))))