Phase 0.3-0.5: SVG export + YAML sidecars + asset catalog

- Add hair class KeyMap entries (基髪→BaseHair, 前髪→FrontHair, 胸毛→ChestHair)
- Implement cardinal spline → cubic Bezier SVG export for all 175 body parts
- Generate YAML sidecar files (part.yaml) per part with metadata
- Write Catalog.yaml index for runtime asset loading
- Output to SlaveMatrix/Assets/Parts/{EnglishName}/ structure
- Each part directory contains part.yaml + x{x}y{y}.svg morph variants
- 838 SVGs across 324 morph variants, 175 sidecars, 1 catalog
- Extraction tool now serves as the asset build pipeline step

SlaveMatrix/Assets/Parts/キャップ左/part.yaml

@@ -0,0 +1,21 @@
+id: キャップ左
+original_key: キャップ左
+resource: 胴体
+morph_x: 1
+morph_y: 1
+variants:
+- x: 0
+  y: 0
+  file: x0y0.svg
+fields:
+- name: 根本
+- name: 先端
+joints:
+- position: [
+  0.062307184933579875,
+  0.06311424522123704
+]
+- position: [
+  0.06359724402559523,
+  0.06940939225806525
+]

SlaveMatrix/Assets/Parts/キャップ左/x0y0.svg

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 1 1">
+<g transform="translate(0.3152081825632307,0.17380834186661692) rotate(0) scale(1,1) translate(-0.06340964978890513,-0.06340964978890513)"><path d="M 0.06266072020893937 0.06061460654518163 C 0.06306414995122947 0.0605065078715323 0.06575109452130362 0.06165886719378818 0.06545576345266285 0.0613635361251474 C 0.06575109452130362 0.06165886719378818 0.0660965943589793 0.06456200911116101 0.06620469303262863 0.06415857936887091 C 0.0660965943589793 0.06456200911116101 0.0637551496265808 0.06631279170627796 0.0641585793688709 0.06620469303262863 C 0.0637551496265808 0.06631279170627796 0.06106820505650664 0.06516043238402208 0.06136353612514741 0.06545576345266285 C 0.06106820505650664 0.06516043238402208 0.06072270521883097 0.062257290466649254 0.06061460654518164 0.06266072020893936 C 0.06072270521883097 0.062257290466649254 0.06306414995122947 0.0605065078715323 0.06266072020893937 0.06061460654518163 Z" fill="#cccccc" stroke="#000000" stroke-width="0.001"/>
+</g><g transform="translate(0.31410571770790546,0.17351293729894884) rotate(0) scale(1,1) translate(-0.06616030380424218,-0.07009616205590638)"><path d="M 0.06296430617816773 0.06664542890540408 C 0.0635484284315395 0.06665821851463266 0.06736223750073668 0.0689097108444153 0.06696030119294308 0.06858581498803461 C 0.06736223750073668 0.0689097108444153 0.06771567913326917 0.07080037457293333 0.06778754187169089 0.07053217918197245 C 0.06771567913326917 0.07080037457293333 0.06558791335043956 0.07188369356547454 0.06609794833188248 0.07180415967956513 C 0.06558791335043956 0.07188369356547454 0.06115486257942572 0.07120560081269584 0.061667122094375776 0.07148658581288529 C 0.06115486257942572 0.07120560081269584 0.0600589328261311 0.06802890993500152 0.05995083415248177 0.06843233967729162 C 0.0600589328261311 0.06802890993500152 0.0635484284315395 0.06665821851463266 0.06296430617816773 0.06664542890540408 Z" fill="#cccccc" stroke="#000000" stroke-width="0.001"/>
+</g></svg>