feat(puppet): v0.3.3 — sprite_rot per-bone render offset

Adds optional 'sprite_rot' field (degrees in JSON, radians stored) to
bone schema. Applied at render: world.rot + sprite_rot. Substrate
convention (puppet.c:295, 2101). Use case: head_001.png has face-right
at rot=0 (asymmetric sprite); without sprite_rot=-90 the look-at result
appears 90° off because math computes rotation assuming sprite-top=
forward but the sprite's natural forward is sprite-right.

Default sprite_rot=0 keeps body, shoulder, arm bones unchanged.

manifest.lib

@@ -1,6 +1,6 @@
 {
     "id": "lib-core.puppet",
-    "version": "0.3.2",
+    "version": "0.3.3",
     "api_min": "0.1",
     "deps": []
 }