fix(gateway): mediaAnalysis ffprobe path, fallback error-log, generic closer sanitize

Audit log produksi (sejak deploy13:38) menemukan 3 isu:
1. mediaDownloader.ts spawn /usr/bin/ffprobe + /usr/bin/ffmpeg (path keras) —
   ENOENT di Nix karena binary cuma di ffmpeg-headless closure. Pakai
   PATH-resolved ('ffprobe'/'ffmpeg') seperti voice-recording module
   (ffmpegProcess.ts/transmitter.ts) — 5 media warning hilang.
2. individualFallbackProcessor log error 'Success' di level50 tiap fallback
   BERHASIL (logModerationError dengan new Error('Success')) — ganti
   logger.info dengan verdict yang sama; error log cuma untuk error asli.
3. moderationResponseParser: strip frasa penutup generik ('Tidak ada
   indikasi pelanggaran.') yang masih sering dikeluarkan LLM walau prompt
   melarang (277/1486 analisis mengandung frasa, termasuk hari ini).
   sanitizeGenericCleanCloser hanya mencocok frasa di AKHIR, teks substantif
   tetap utuh. Unit test: 6/6 pass.

services/discord-gateway/src/modules/ai-moderation/individualFallbackProcessor.ts

@@ -155,13 +155,16 @@ async function processIndividualFallback(
     }
 
     const resultSummary = analysisResult.results[0];
-    logModerationError([messageId], config.AI_LLM_MODEL, new Error("Success"), {
-      phase: "individual_fallback",
-      status: resultSummary?.status,
-      flags: resultSummary?.flags,
-      severity: resultSummary?.severity,
-      confidence: resultSummary?.confidence,
-    });
+    logger.info(
+      {
+        phase: "individual_fallback",
+        status: resultSummary?.status,
+        flags: resultSummary?.flags,
+        severity: resultSummary?.severity,
+        confidence: resultSummary?.confidence,
+      },
+      `Individual fallback moderation complete for ${messageId} (${resultSummary?.status})`,
+    );
 
     individualConsecutiveErrors = 0;
 

services/discord-gateway/src/modules/ai-moderation/mediaDownloader.ts

@@ -198,7 +198,7 @@ async function extractVideoFrames(
   try {
     await writeFile(inputPath, videoBytes);
     const { stdout: durationStr } = await execFileAsync(
-      "/usr/bin/ffprobe",
+      "ffprobe",
       [
         "-v",
         "error",
@@ -213,7 +213,7 @@ async function extractVideoFrames(
     const duration = parseFloat(durationStr.trim()) || 1;
     const fps = (3 / duration).toFixed(6);
     await execFileAsync(
-      "/usr/bin/ffmpeg",
+      "ffmpeg",
       [
         "-i",
         inputPath,

services/discord-gateway/src/modules/ai-moderation/moderationResponseParser.ts

@@ -157,6 +157,22 @@ export function sanitizeErrorMessage(
   return `Analisis gagal dan memerlukan pemeriksaan manual. Error code: MOD_${Date.now().toString(36).slice(0, 6)}`;
 }
 
+/**
+ * Strip generic clean-verdict closing phrases the LLM sometimes appends
+ * ("Tidak ada indikasi pelanggaran.") even when it already described the
+ * message content specifically. Keeps the substance, drops the boilerplate.
+ * Only matches a TRAILING standalone phrase — never mid-analysis text.
+ */
+export const GENERIC_CLEAN_CLOSER =
+  /\s*(?:(?:tidak ada (?:indikasi|tanda|temuan)(?: adanya)? pelanggaran(?: kebijakan| aturan)?)|(?:tidak ada (?:indikasi|tanda|temuan)(?: konten| pesan)? (?:yang )?melanggar)|(?:pesan (?:dianggap|tergolong|dinilai) bersih)|(?:tidak ditemukan (?:adanya )?pelanggaran))\.?\s*$/i;
+
+export function sanitizeGenericCleanCloser(analysis: string): string {
+  if (!analysis) return analysis;
+  const cleaned = analysis.replace(GENERIC_CLEAN_CLOSER, "").trim();
+  // Drop a dangling separator the removal may have left behind.
+  return cleaned.replace(/(\s[.\-–—]\s*)$/, "").trim();
+}
+
 export function parseModerationResponse(
   content: string,
   targetIds: string[],
@@ -250,7 +266,7 @@ export function parseModerationResponse(
       status: status as "clean" | "warn" | "flagged",
       flags: flags ?? [],
       score: normalizedScore,
-      analysis: coalescedAnalysis,
+      analysis: sanitizeGenericCleanCloser(coalescedAnalysis),
       categories: categories ?? flags ?? [],
       severity: normalizedSeverity,
       confidence: normalizedConfidence,