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>

tests/moderation/indonesianTextNormalizer.test.ts

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+import { describe, expect, it } from "vitest";
+import {
+  buildModerationTextEvidence,
+  detectIndonesianBadwords,
+  formatModerationTextEvidenceForPrompt,
+  normalizeDiscordCustomEmoji,
+  normalizeIndonesianSlang,
+} from "../../src/moderation/indonesianTextNormalizer";
+
+describe("normalizeDiscordCustomEmoji", () => {
+  it("replaces static custom emoji", () => {
+    const result = normalizeDiscordCustomEmoji("Bersiaplah woy <:hadeh:1217434294281048185>");
+    expect(result.text).toBe("Bersiaplah woy [emoji:hadeh]");
+    expect(result.emojiNames).toContain("hadeh");
+  });
+
+  it("replaces animated custom emoji", () => {
+    const result = normalizeDiscordCustomEmoji("cek <a:speen:1234567890> dulu");
+    expect(result.text).toBe("cek [emoji:speen] dulu");
+    expect(result.emojiNames).toContain("speen");
+  });
+
+  it("handles text without emoji", () => {
+    const result = normalizeDiscordCustomEmoji("halo semua");
+    expect(result.text).toBe("halo semua");
+    expect(result.emojiNames).toHaveLength(0);
+  });
+});
+
+describe("normalizeIndonesianSlang", () => {
+  it("maps common slang to normalized form", () => {
+    const { text, notes } = normalizeIndonesianSlang("gw emg kyk gitu");
+    expect(text).toBe("gue memang kayak gitu");
+    expect(notes.some((n) => n.startsWith("gw="))).toBe(true);
+  });
+
+  it("marks woy as safe casual interjection", () => {
+    const { text, notes } = normalizeIndonesianSlang("woy hadeh");
+    expect(text).toBe("woy hadeh");
+    expect(notes.some((n) => n.includes("casual"))).toBe(true);
+  });
+});
+
+describe("detectIndonesianBadwords", () => {
+  it("detects known badword", () => {
+    const badwords = detectIndonesianBadwords("kontol banget");
+    expect(badwords).toContain("kontol");
+  });
+
+  it("returns empty array for safe slang", () => {
+    const badwords = detectIndonesianBadwords("woy hadeh gua");
+    expect(badwords).toHaveLength(0);
+  });
+});
+
+describe("buildModerationTextEvidence", () => {
+  it("produces correct evidence for woy with emoji", () => {
+    const evidence = buildModerationTextEvidence(
+      "Bersiaplah woy <:hadeh:1217434294281048185>",
+    );
+    expect(evidence.normalized).toContain("[emoji:hadeh]");
+    expect(evidence.badwords).toHaveLength(0);
+    expect(evidence.hasBadwords).toBe(false);
+    expect(evidence.notes.some((n) => n.includes("no Indonesian badword"))).toBe(true);
+    expect(evidence.notes.some((n) => n.includes("emoji:hadeh"))).toBe(true);
+    expect(evidence.notes.some((n) => n.includes("casual"))).toBe(true);
+  });
+
+  it("detects badword when present", () => {
+    const evidence = buildModerationTextEvidence("anjing loe kontol");
+    expect(evidence.hasBadwords).toBe(true);
+    expect(evidence.notes.some((n) => n.includes("badword detected"))).toBe(true);
+  });
+});
+
+describe("formatModerationTextEvidenceForPrompt", () => {
+  it("returns prompt evidence for slang + emoji", () => {
+    const formatted = formatModerationTextEvidenceForPrompt(
+      "Bersiaplah woy <:hadeh:1217434294281048185>",
+    );
+    expect(formatted).toContain("[normalized_text:");
+    expect(formatted).toContain("[emoji:hadeh]");
+    expect(formatted).toContain("[normalization_notes:");
+    expect(formatted).toContain("no Indonesian badword detected");
+  });
+
+  it("includes normalized text even for clean input", () => {
+    const formatted = formatModerationTextEvidenceForPrompt("Halo semua");
+    expect(formatted).toContain("[normalized_text:");
+    expect(formatted).toContain("no Indonesian badword detected");
+  });
+});