feat: Add per-type NPC icons + update compendium icons

6 new SVG icons in images/icons/, one per NPC type:
- icon-npc-esprit-animal.svg (amber) — paw print + yin-yang
- icon-npc-fantome.svg (cyan) — ghost silhouette + 鬼 character
- icon-npc-demon.svg (red) — horned demon face
- icon-npc-jiugwaai.svg (emerald) — hybrid creature + 怪 character
- icon-npc-dieu.svg (gold) — divine halo + lotus
- icon-npc-mortel.svg (steel blue) — human silhouette + talisman

All 49 NPC JSON files updated with type-specific icon paths.
Pack cde-npcs recompiled.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

packs-src/cde-npcs/Taotie_tetes_volantes.json

@@ -3,7 +3,7 @@
   "_key": "!actors!TeSKf4HhtefN6eUO",
   "name": "Taotie (têtes volantes)",
   "type": "npc",
-  "img": "systems/fvtt-chroniques-de-l-etrange/images/icons/icon-npc.svg",
+  "img": "systems/fvtt-chroniques-de-l-etrange/images/icons/icon-npc-demon.svg",
   "system": {
     "type": "demon",
     "threat": 1,