feat: Tdarr Local Flow Plugin Suite v1.0

7 atomic plugins for automated x265 transcoding pipeline:
- utility/mediaAnalyzerGOP    : GOP calc, FPS detection, film/series/anime routing
- utility/setAnimationFlag    : manual animation flag override
- utility/extractChaptersXml  : mkvextract chapters to XML
- audio/audioSelectorClamping : codec scoring, clamped Opus bitrates, 2 outputs
- audio/backupSourceAudio     : lossless DTS/TrueHD ITA backup (-c:a copy)
- subtitles/extractSubtitlesAndOcr : SRT extract + SubtitleEdit OCR for PGS
- video/transcode2PassX265    : 2-pass x265, Lanczos 1080p bound, Opus mux

Test suite: 34 unit tests + 3 integration tests (FFmpeg real files)
FlowHelpers mock for local testing included
Docs: integration-guide.md with canvas wiring and deploy instructions

tests/mock-tdarr-runtime.js

@@ -0,0 +1,109 @@
+'use strict';
+
+/**
+ * mock-tdarr-runtime.js
+ * Creates a complete mock of the Tdarr args object for isolated plugin testing.
+ * Supports loading real ffprobe data from actual MKV files.
+ */
+
+const path = require('path');
+const os   = require('os');
+const fs   = require('fs');
+const { execSync } = require('child_process');
+
+/**
+ * Run ffprobe on a file and return parsed JSON.
+ * Falls back to a minimal synthetic structure if ffprobe is unavailable.
+ */
+function probeFile(filePath) {
+  try {
+    const raw = execSync(
+      `ffprobe -v quiet -print_format json -show_streams -show_format "${filePath}"`,
+      { encoding: 'utf8', timeout: 15000 },
+    );
+    return JSON.parse(raw);
+  } catch (err) {
+    console.warn(`[mock] ffprobe failed for ${filePath}: ${err.message}`);
+    return { streams: [], format: {} };
+  }
+}
+
+/**
+ * Build a mock Tdarr args object.
+ *
+ * @param {object} opts
+ * @param {string}  opts.filePath     - Path to the input MKV file
+ * @param {object}  [opts.inputs]     - Plugin input overrides (UI inputs)
+ * @param {object}  [opts.variables]  - Pre-populated variables
+ * @param {string}  [opts.ffmpegPath] - Override ffmpeg path
+ * @param {string}  [opts.workDir]    - Override work directory
+ */
+function buildMockArgs(opts) {
+  const {
+    filePath,
+    inputs    = {},
+    variables = {},
+    ffmpegPath = process.env.FFMPEG_PATH || 'ffmpeg',
+    workDir   = fs.mkdtempSync(path.join(os.tmpdir(), 'tdarr-test-')),
+  } = opts;
+
+  const ffProbeData = probeFile(filePath);
+  const logs = [];
+
+  return {
+    inputFileObj: {
+      _id: filePath,
+      file: filePath,
+      ffProbeData,
+      mediaInfo: { track: [] },
+      container: path.extname(filePath).replace('.', ''),
+    },
+    variables:   { ...variables },
+    inputs,
+    workDir,
+    ffmpegPath,
+    ffprobePath:       process.env.FFPROBE_PATH   || 'ffprobe',
+    mkvpropeditPath:   process.env.MKVPROPEDIT_PATH || 'mkvpropedit',
+    userVariables: { global: {}, library: {} },
+    jobLog: (msg) => {
+      process.stdout.write(msg);
+      logs.push(msg);
+    },
+    _logs: logs,
+    _workDir: workDir,
+  };
+}
+
+/**
+ * Cleanup a workDir created by buildMockArgs.
+ */
+function cleanupWorkDir(mockArgs) {
+  const dir = mockArgs._workDir || mockArgs.workDir;
+  if (dir && dir.startsWith(os.tmpdir()) && fs.existsSync(dir)) {
+    fs.rmSync(dir, { recursive: true, force: true });
+  }
+}
+
+/**
+ * Simple assertion helper.
+ */
+function assert(condition, message) {
+  if (!condition) throw new Error(`ASSERTION FAILED: ${message}`);
+  console.log(`  [OK] ${message}`);
+}
+
+function assertEqual(actual, expected, label) {
+  assert(
+    actual === expected,
+    `${label}: expected "${expected}", got "${actual}"`,
+  );
+}
+
+function assertLessOrEqual(actual, max, label) {
+  assert(
+    parseInt(actual, 10) <= max,
+    `${label}: ${actual} <= ${max}`,
+  );
+}
+
+module.exports = { buildMockArgs, cleanupWorkDir, assert, assertEqual, assertLessOrEqual };