refactor: deduplicate prompts, reorganize persona files, update paths

Prompt deduplication (~20% reduction, 4,743 chars saved):
- evil_miku_lore.txt: remove intra-file duplication (height rule 2x,
  cruelty-has-substance 2x, music secret 2x, adoration secret 2x),
  trim verbose restatements, cut speech examples from 10 to 6
- evil_miku_prompt.txt: remove entire PERSONALITY section (in lore),
  remove entire RESPONSE STYLE section (now only in preamble),
  soften height from prohibition to knowledge
- miku_lore.txt: remove RELATIONSHIPS section (duplicates FRIENDS)
- miku_prompt.txt: remove duplicate intro, 4 personality traits
  already in lore, FAMOUS SONGS section (in lore), fix response
  length inconsistency (1-2 vs 2-3 -> consistent 2-3)

Preamble updates (evil_mode.py, evil_miku_personality.py, llm.py,
miku_personality.py):
- Response rules now exist in ONE place only (preamble)
- Height rule softened: model knows 15.8m, can say it if asked,
  but won't default to quoting it when taunting
- Response length: 2-4 sentences (was 1-3), removed action template
  list that model was copying literally (*scoffs*, *rolls eyes*)
- Added: always include actual words, never action-only responses
- Normal Miku: trim CHARACTER CONTEXT, fix 1-3 -> 2-3 sentences

Directory reorganization:
- Move 6 persona files to bot/persona/{evil,miku}/ subdirectories
- Update all open() paths in evil_mode.py, context_manager.py,
  voice_manager.py, both Cat plugins
- Dockerfile: 6 COPY lines -> 1 (COPY persona /app/persona)
- docker-compose: 6 file mounts -> 2 directory mounts
  (bot/persona/evil -> cat/data/evil, bot/persona/miku -> cat/data/miku)

Evil Miku system (previously unstaged):
- Full evil mood management: 2h rotation timer, mood persistence,
  10 mood-specific autonomous template pools, mood-aware DMs
- Evil mode toggle with role color/nickname/pfp management
- get_evil_system_prompt() with mood integration

Add test_evil_moods.py: 10-mood x 3-message comprehensive test

bot/utils/context_manager.py

@@ -17,7 +17,7 @@ logger = get_logger('core')
 def get_original_miku_lore() -> str:
     """Load the complete, unmodified miku_lore.txt file"""
     try:
-        with open("miku_lore.txt", "r", encoding="utf-8") as f:
+        with open("persona/miku/miku_lore.txt", "r", encoding="utf-8") as f:
             return f.read()
     except Exception as e:
         logger.error(f"Failed to load miku_lore.txt: {e}")
@@ -27,7 +27,7 @@ def get_original_miku_lore() -> str:
 def get_original_miku_prompt() -> str:
     """Load the complete, unmodified miku_prompt.txt file"""
     try:
-        with open("miku_prompt.txt", "r", encoding="utf-8") as f:
+        with open("persona/miku/miku_prompt.txt", "r", encoding="utf-8") as f:
             return f.read()
     except Exception as e:
         logger.error(f"Failed to load miku_prompt.txt: {e}")
@@ -37,7 +37,7 @@ def get_original_miku_prompt() -> str:
 def get_original_miku_lyrics() -> str:
     """Load the complete, unmodified miku_lyrics.txt file"""
     try:
-        with open("miku_lyrics.txt", "r", encoding="utf-8") as f:
+        with open("persona/miku/miku_lyrics.txt", "r", encoding="utf-8") as f:
             return f.read()
     except Exception as e:
         logger.error(f"Failed to load miku_lyrics.txt: {e}")