fix: initialize slices explicitly and improve uniqueness check robustness

- Initialize list slices with make() to avoid nil slices in ListTempEntries and ListPermEntries
- Use strings.Contains() for uniqueness constraint checking to handle variations in error messages

db.go

@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"log/slog"
 	"net"
+	"strings"
 	"time"
 
 	_ "modernc.org/sqlite"
@@ -173,7 +174,7 @@ func ListTempEntries(db *sql.DB) ([]map[string]interface{}, error) {
 		return nil, err
 	}
 	defer rows.Close()
-	var list []map[string]interface{}
+	var list []map[string]interface{} = make([]map[string]interface{}, 0)
 	for rows.Next() {
 		var ip, reason string
 		var expiresAt time.Time
@@ -195,7 +196,7 @@ func ListPermEntries(db *sql.DB) ([]map[string]interface{}, error) {
 		return nil, err
 	}
 	defer rows.Close()
-	var list []map[string]interface{}
+	var list []map[string]interface{} = make([]map[string]interface{}, 0)
 	for rows.Next() {
 		var entry string
 		if err := rows.Scan(&entry); err != nil {
@@ -240,5 +241,5 @@ func isUniqueConstraintError(err error) bool {
 	if err == nil {
 		return false
 	}
-	return err.Error() == "UNIQUE constraint failed: perm_whitelist.entry"
+	return strings.Contains(err.Error(), "UNIQUE constraint failed")
 }