doctor: add fs fault injection and lock contention coverage

Co-authored-by: factory-droid[bot] <138933559+factory-droid[bot]@users.noreply.github.com>

cmd/bd/doctor/config_values.go

@@ -357,7 +357,7 @@ func checkDatabaseConfigValues(repoPath string) []string {
 	}
 
 	// Open database in read-only mode
-	db, err := sql.Open("sqlite3", "file:"+dbPath+"?mode=ro")
+	db, err := sql.Open("sqlite3", sqliteConnString(dbPath, true))
 	if err != nil {
 		return issues // Can't open database, skip
 	}