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>

src/moderation/conversationContext.ts

@@ -1,3 +1,4 @@
+import { formatModerationTextEvidenceForPrompt } from "./indonesianTextNormalizer.js";
 import { formatMediaEvidenceForPrompt } from "./messageMetadata.js";
 import type { MessageRecord } from "./types.js";
 
@@ -30,9 +31,11 @@ export function formatMessageForPrompt(
 ): string {
   const content = msg.edited_content ?? msg.content;
   const timestamp = formatTimestamp(msg.created_at);
+  const textEvidence = formatModerationTextEvidenceForPrompt(content);
+  const textSuffix = textEvidence ? ` ${textEvidence}` : "";
   const mediaEvidence = formatMediaEvidenceForPrompt(msg.metadata);
   const mediaSuffix = mediaEvidence ? ` ${mediaEvidence}` : "";
-  return `[${label}] id=${msg.id} time=${timestamp} user=${msg.username}: ${content}${mediaSuffix}`;
+  return `[${label}] id=${msg.id} time=${timestamp} user=${msg.username}: ${content}${textSuffix}${mediaSuffix}`;
 }
 
 /**