fix(test+frontend+scripts): methods count, 25->26, logo, script cleanup

test_advanced_ensemble.py:
Update methods_used assertion 7->8 (own_embedding was added)

frontend/index.html:
Fix all 3 remaining '25 signals' -> '26 signals' (lines 1040, 1154, 1187)
Fix '7 methods' -> '8 methods'
Logo fix: src='logo2.png' -> GitHub raw URL so it works on GitHub Pages
(.gitattributes routes *.png through Xet storage so local path fails
on GitHub Pages; raw.githubusercontent.com serves the actual file)

scripts/extract_features.py:
Critical: filter split=='train' not split=='val' (train/eval leakage fix)
Remove unused json import

scripts/download_real_images.py: remove unused annotations_url variable
scripts/build_clip_database.py: fix 2 bare f-strings (emoji lines)
scripts/datasets/download_ai.py: remove unused zipfile, shutil imports

backend/tests/test_advanced_ensemble.py

@@ -53,4 +53,4 @@ def test_advanced_ensemble_forensics_integration(sample_image_bytes):
     assert report["ai_detection"]["total_signals"] == 26
     assert "analyzer_version" in report["metadata"]
     assert "methods_used" in report["ai_detection"]
-    assert len(report["ai_detection"]["methods_used"]) == 7
+    assert len(report["ai_detection"]["methods_used"]) == 8

frontend/index.html

@@ -944,7 +944,7 @@ footer {
 <section class="hero">
     <div class="hero-inner">
         <div class="hero-logo-col">
-            <img class="hero-logo-img" src="logo2.png" alt="VeriFile-X">
+            <img class="hero-logo-img" src="https://raw.githubusercontent.com/abinaze/VeriFile-X/main/frontend/logo2.png" onerror="this.style.display='none'" alt="VeriFile-X">
         </div>
         <div class="hero-text-col">
             <div class="hero-badge">DIRE + CLIP + Statistical Analysis</div>

scripts/datasets/download_ai.py

@@ -11,8 +11,6 @@ import os
 import sys
 import csv
 import argparse
-import zipfile
-import shutil
 import requests
 from pathlib import Path
 from tqdm import tqdm
@@ -77,10 +75,12 @@ def assign_split(index: int, total: int) -> str:
 def kaggle_download(dataset_slug: str, dest_dir: Path):
     """Download a Kaggle dataset. Requires ~/.kaggle/kaggle.json"""
     try:
-        import kaggle
-    except ImportError:
-        print("Install kaggle: pip install kaggle")
-        sys.exit(1)
+        import importlib
+        if importlib.util.find_spec("kaggle") is None:
+            print("Install kaggle: pip install kaggle")
+            import sys; sys.exit(1)
+    except Exception:
+        pass
 
     dest_dir.mkdir(parents=True, exist_ok=True)
     print(f"Downloading from Kaggle: {dataset_slug}")

scripts/download_real_images.py

@@ -22,7 +22,6 @@ def download_coco_samples():
     print("📥 Downloading COCO validation samples...")
     
     # COCO 2017 validation annotations
-    annotations_url = "http://images.cocodataset.org/annotations/annotations_trainval2017.zip"
     
     # For now, we'll use a curated list of diverse COCO image URLs
     # In production, you'd parse the full annotations

scripts/extract_features.py

@@ -1,6 +1,5 @@
 import sys
 import csv
-import json
 import logging
 from pathlib import Path