feat(moderation): Indonesian slang normalizer and false-positive prevention

- Add indonesian-badwords dependency for local lexical signal
- Add Indonesian slang lexicon with woy/woi/hadeh as safe casual terms
- Normalize Discord custom emoji <:name:id> to [emoji:name] in prompts
- Wire normalization evidence into both conversationContext and llmModerationClient prompts
- Harden system prompt: woy/woi are casual greetings, not SARA/hate
- Add tests for emoji normalization, slang mapping, badword detection

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

package.json

@@ -42,6 +42,7 @@
     "drizzle-orm": "^0.45.2",
     "express": "^5.2.1",
     "helmet": "^8.1.0",
+    "indonesian-badwords": "^1.0.1",
     "libsodium-wrappers": "^0.8.4",
     "lucide-react": "^1.16.0",
     "openai": "^6.38.0",