- Add dbPath field to SQLiteStorage to track database file path
- Create derivePrefixFromPath() helper to extract prefix from filename
- Update ID generation in CreateIssue() and generateBatchIDs() to use filename fallback
- Fix tests to explicitly set issue_prefix config for bd- prefixed tests
When config doesn't have issue_prefix set, bd now correctly derives it from
the database filename (e.g., wy-.db -> wy) instead of always defaulting to 'bd'.
Fixes: bd-179
db8efd534c