docs: verify issue #605 video scenes dataset

Add a verification note and regression test showing that
training/data/prompt-enhancement/video-scenes-500.jsonl already
exists on main with 500 valid records.

docs/issue-605-verification.md

@@ -0,0 +1,46 @@
+# Issue #605 Verification
+
+Status: already implemented on `main`.
+
+Issue: Prompt Enhancement: Video Scenes — 500 Terse→Rich Pairs
+
+What is already present on `main`
+- `training/data/prompt-enhancement/video-scenes-500.jsonl`
+- 500 JSONL records
+- every record includes `terse`, `rich`, and `domain`
+- every `domain` value is `video scenes`
+- 500/500 full records are unique
+- every `rich` prompt includes video-scene structure markers for `lighting`, `composition`, and `transition`
+
+Evidence gathered from a fresh clone
+- validation against `training/data/prompt-enhancement/video-scenes-500.jsonl` returned:
+  - `count = 500`
+  - `unique_records = 500`
+  - `unique_terse = 120`
+  - `domains = ['video scenes']`
+  - `missing_keys = 0`
+  - all 500 `rich` prompts contain `lighting`, `composition`, and `transition`
+- closed PRs `#755` (`fix/605`) and `#648` (`feat/605-video-scenes-prompts`) show prior attempts on this lane
+- SHA-256 of `training/data/prompt-enhancement/video-scenes-500.jsonl` on `origin/main` matches the same file on remote branch `fix/605`, which shows the requested dataset is already present on `main`
+
+Verification commands
+```bash
+python3 - <<'PY'
+import json
+from pathlib import Path
+path = Path('training/data/prompt-enhancement/video-scenes-500.jsonl')
+records = [json.loads(line) for line in path.read_text().splitlines() if line.strip()]
+print('count', len(records))
+print('unique_records', len({json.dumps(r, sort_keys=True) for r in records}))
+print('unique_terse', len({r['terse'] for r in records}))
+print('domains', sorted({r.get('domain') for r in records}))
+print('missing_keys', sum(any(k not in r or not str(r[k]).strip() for k in ('terse', 'rich', 'domain')) for r in records))
+print('lighting_count', sum('lighting' in r['rich'].lower() for r in records))
+print('composition_count', sum('composition' in r['rich'].lower() for r in records))
+print('transition_count', sum('transition' in r['rich'].lower() for r in records))
+PY
+```
+
+Recommendation
+- Close issue #605 as already implemented on `main`.
+- This branch only adds a durable verification note and regression test so the open issue can be closed cleanly without regenerating duplicate training data.

tests/test_prompt_enhancement_video_scenes.py

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+#!/usr/bin/env python3
+"""Verification tests for timmy-config issue #605."""
+
+import json
+import unittest
+from pathlib import Path
+
+ROOT = Path(__file__).resolve().parent.parent
+DATA_PATH = ROOT / "training" / "data" / "prompt-enhancement" / "video-scenes-500.jsonl"
+DOC_PATH = ROOT / "docs" / "issue-605-verification.md"
+
+
+def load_records():
+    with DATA_PATH.open("r", encoding="utf-8") as handle:
+        return [json.loads(line) for line in handle if line.strip()]
+
+
+class TestVideoScenesPromptEnhancement(unittest.TestCase):
+    def test_dataset_exists(self):
+        self.assertTrue(DATA_PATH.exists(), f"Missing dataset: {DATA_PATH}")
+
+    def test_dataset_has_500_records(self):
+        self.assertEqual(len(load_records()), 500)
+
+    def test_schema_and_domain(self):
+        for idx, record in enumerate(load_records(), start=1):
+            for key in ("terse", "rich", "domain"):
+                self.assertIn(key, record, f"line {idx}: missing {key}")
+                self.assertIsInstance(record[key], str, f"line {idx}: {key} must be a string")
+                self.assertTrue(record[key].strip(), f"line {idx}: {key} is empty")
+            self.assertEqual(record["domain"], "video scenes", f"line {idx}: wrong domain")
+
+    def test_records_are_unique(self):
+        records = load_records()
+        serialized = [json.dumps(record, sort_keys=True) for record in records]
+        self.assertEqual(len(serialized), len(set(serialized)), "duplicate full records found")
+
+    def test_rich_prompts_include_video_scene_markers(self):
+        for idx, record in enumerate(load_records(), start=1):
+            rich = record["rich"].lower()
+            self.assertIn("lighting", rich, f"line {idx}: rich prompt missing lighting")
+            self.assertIn("composition", rich, f"line {idx}: rich prompt missing composition")
+            self.assertIn("transition", rich, f"line {idx}: rich prompt missing transition")
+
+    def test_verification_doc_exists_and_mentions_evidence(self):
+        self.assertTrue(DOC_PATH.exists(), f"Missing verification doc: {DOC_PATH}")
+        text = DOC_PATH.read_text(encoding="utf-8")
+        self.assertIn("Issue #605 Verification", text)
+        self.assertIn("training/data/prompt-enhancement/video-scenes-500.jsonl", text)
+        self.assertIn("#755", text)
+        self.assertIn("already implemented on `main`", text)
+
+
+if __name__ == "__main__":
+    unittest.main()