feat(evil-miku): add 10-mood system and Evil Miku Cat plugin

- Add 6 new evil mood files: bored, contemptuous, jealous, manic,
  melancholic, playful_cruel
- Rewrite 4 existing mood files: aggressive, cunning, evil_neutral,
  sarcastic (shorter, more focused descriptions)
- Add evil_miku_personality Cat plugin (parallel to miku_personality)
  with mood-aware system prompt, softened height rule, and balanced
  response length rules (2-4 sentences)

cat-plugins/evil_miku_personality/plugin.json

@@ -0,0 +1,10 @@
+{
+    "name": "Evil Miku Personality",
+    "version": "0.1.0",
+    "description": "Makes Cheshire Cat act as Evil Miku - the dark, twisted version of Hatsune Miku",
+    "author_name": "Koko",
+    "author_url": "",
+    "plugin_url": "",
+    "tags": "personality",
+    "thumb": ""
+}