docs: make SQLite environment example runnable

.env.example

@@ -16,7 +16,9 @@ LOG_LEVEL='info'
 
 # This is how you can use the sqlite driver:
 DB_DRIVER='better-sqlite3'
-DB_URL='FULL_PATH_TO_YOUR_SQLITE_DB_FILE'
+# Safe local source-development path. SQLite files are ignored by Git.
+# Container images use /appdata/db/db.sqlite by default instead.
+DB_URL='./db.sqlite'
 
 # Those are the two ways to use the mysql2 driver:
 # 1. Using the URL format: