Summary

openDatabase without readOnly creates the file if it does not exist. Test Connection and Table Browser on a typo path (/tmp/oops.db) leave an empty .db on disk and look like a successful empty catalog.

Scope

• For an existing saved connection, open with a flag that fails if the file is absent (or stat first). Creating a new connection from the form may still create the file — only after the user confirms Save, not on Test.
• Clear error: file not found vs corrupt vs permission.
• Tests: testConnection / connect on a missing path does not create the file.

Out of scope

• In-memory inMemoryDatabasePath (tests / demo).