Cryptographic Hash Extractor v0.5.1

Changed

• Version bumped to v0.5.1 in version label and window title (main.py)
• SUPPORTED_EXTENSIONS in readers.py is now derived from _DISPATCH keys, eliminating the risk of the two sets drifting out of sync
• Directory existence check in search() replaced with os.path.isdir() directly, removing a redundant HashExtractor instantiation

Fixed

• Added closeEvent to pdfAnalysis that stops and waits for any running scan thread before the dialog closes, preventing a crash on close during an active scan
• SQLite foreign key enforcement enabled via PRAGMA foreign_keys = ON in HashDatabase._connect() — the REFERENCES scans(id) constraint on hash_results was previously decorative only
• Removed truncated/broken comment block in db.py that was left mid-sentence above the HashDatabase class definition