fix(db): quote SQLCipher PRAGMA hex key to fix fresh install crash

The hex-encoded encryption key (x'...') is not valid as a bare PRAGMA
value in better-sqlite3. Wrapping it in double quotes produces valid
SQLCipher PRAGMA syntax.

Fixes #3

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

CHANGELOG.md

@@ -7,6 +7,11 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [Unreleased]
 
+## [0.5.4] - 2026-04-03
+
+### Fixed
+- Fix SQLCipher PRAGMA key syntax error on fresh install — hex-encoded key must be wrapped in double quotes for valid PRAGMA syntax (fixes #3)
+
 ## [0.5.3] - 2026-04-03
 
 ### Security