feat: implement AI integration with backend configuration and rule-based enrichment actions

internal/db/db.go

@@ -139,6 +139,12 @@ func (d *DB) migrate() error {
 		created_at DATETIME NOT NULL,
 		updated_at DATETIME NOT NULL
 	);
+
+	CREATE TABLE IF NOT EXISTS system_settings (
+		key TEXT PRIMARY KEY,
+		value TEXT NOT NULL,
+		updated_at DATETIME NOT NULL
+	);
 	`
 	if _, err := d.Exec(schema); err != nil {
 		return err
@@ -1067,3 +1073,46 @@ func (d *DB) GetStats() (*models.Stats, error) {
 	_ = d.QueryRow("SELECT COUNT(*) FROM rules").Scan(&s.TotalRules)
 	return &s, nil
 }
+
+// System Settings CRUD
+func (d *DB) GetSetting(key string) (string, error) {
+	var val string
+	err := d.QueryRow("SELECT value FROM system_settings WHERE key = ?", key).Scan(&val)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			return "", nil
+		}
+		return "", err
+	}
+	return val, nil
+}
+
+func (d *DB) SetSetting(key, value string) error {
+	now := time.Now().UTC()
+	_, err := d.Exec(`
+		INSERT INTO system_settings (key, value, updated_at)
+		VALUES (?, ?, ?)
+		ON CONFLICT(key) DO UPDATE SET value = excluded.value, updated_at = excluded.updated_at
+	`, key, value, now)
+	return err
+}
+
+func (d *DB) GetSettingsMap() (map[string]string, error) {
+	rows, err := d.Query("SELECT key, value FROM system_settings")
+	if err != nil {
+		return nil, err
+	}
+	defer func() {
+		_ = rows.Close()
+	}()
+
+	res := make(map[string]string)
+	for rows.Next() {
+		var k, v string
+		if err := rows.Scan(&k, &v); err != nil {
+			return nil, err
+		}
+		res[k] = v
+	}
+	return res, nil
+}