Add retry mechanism and failure notifications for nCore/qBittorrent setup

- Implemented a retry mechanism for external calls, allowing up to 3 attempts before failing.
- Enhanced error handling to send failure notifications when setup steps fail, including detailed error messages.
- Updated RunSummary model to include status, error step, and error message fields for better tracking of run outcomes.
- Modified database schema to store failure metadata for runs.
- Updated README.md to reflect changes in error handling and notification behavior.

internal/store/store.go

@@ -135,10 +135,17 @@ func (s *Store) MarkManualNeeded(id int64, now time.Time) error {
 }
 
 func (s *Store) InsertRun(summary model.RunSummary) error {
+	status := summary.Status
+	if status == "" {
+		status = "success"
+	}
 	_, err := s.db.Exec(`
-		INSERT INTO runs (started_at, dry_run, total_risk, matched, unmatched, force_started, reannounced, manual_needed)
-		VALUES (?, ?, ?, ?, ?, ?, ?, ?)
-	`, summary.StartedAt.Format(time.RFC3339), boolInt(summary.DryRun), summary.TotalRisk, summary.Matched, summary.Unmatched, summary.ForceStarted, summary.Reannounced, summary.ManualNeeded)
+		INSERT INTO runs (
+			started_at, status, error_step, error_message, dry_run,
+			total_risk, matched, unmatched, force_started, reannounced, manual_needed
+		)
+		VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, ?, ?)
+	`, summary.StartedAt.Format(time.RFC3339), status, summary.ErrorStep, summary.ErrorMessage, boolInt(summary.DryRun), summary.TotalRisk, summary.Matched, summary.Unmatched, summary.ForceStarted, summary.Reannounced, summary.ManualNeeded)
 	return err
 }
 
@@ -215,11 +222,22 @@ func (s *Store) lastRun() (*model.RunRecord, error) {
 	var run model.RunRecord
 	var dryRun int
 	err := s.db.QueryRow(`
-		SELECT started_at, dry_run, total_risk, matched, unmatched, force_started, reannounced, manual_needed
+		SELECT
+			started_at,
+			status,
+			COALESCE(error_step, ''),
+			COALESCE(error_message, ''),
+			dry_run,
+			total_risk,
+			matched,
+			unmatched,
+			force_started,
+			reannounced,
+			manual_needed
 		FROM runs
 		ORDER BY id DESC
 		LIMIT 1
-	`).Scan(&run.StartedAt, &dryRun, &run.TotalRisk, &run.Matched, &run.Unmatched, &run.ForceStarted, &run.Reannounced, &run.ManualNeeded)
+	`).Scan(&run.StartedAt, &run.Status, &run.ErrorStep, &run.ErrorMessage, &dryRun, &run.TotalRisk, &run.Matched, &run.Unmatched, &run.ForceStarted, &run.Reannounced, &run.ManualNeeded)
 	if err == sql.ErrNoRows {
 		return nil, nil
 	}
@@ -327,6 +345,9 @@ func (s *Store) migrate() error {
 		CREATE TABLE IF NOT EXISTS runs (
 			id INTEGER PRIMARY KEY AUTOINCREMENT,
 			started_at TEXT NOT NULL,
+			status TEXT NOT NULL DEFAULT 'success',
+			error_step TEXT,
+			error_message TEXT,
 			dry_run INTEGER NOT NULL,
 			total_risk INTEGER NOT NULL,
 			matched INTEGER NOT NULL,
@@ -336,6 +357,47 @@ func (s *Store) migrate() error {
 			manual_needed INTEGER NOT NULL
 		);
 	`)
+	if err != nil {
+		return err
+	}
+	if err := s.addColumnIfMissing("runs", "status", "TEXT NOT NULL DEFAULT 'success'"); err != nil {
+		return err
+	}
+	if err := s.addColumnIfMissing("runs", "error_step", "TEXT"); err != nil {
+		return err
+	}
+	if err := s.addColumnIfMissing("runs", "error_message", "TEXT"); err != nil {
+		return err
+	}
+	return err
+}
+
+func (s *Store) addColumnIfMissing(table string, column string, definition string) error {
+	rows, err := s.db.Query(fmt.Sprintf(`PRAGMA table_info(%s)`, table))
+	if err != nil {
+		return err
+	}
+	defer rows.Close()
+
+	for rows.Next() {
+		var cid int
+		var name string
+		var columnType string
+		var notNull int
+		var defaultValue sql.NullString
+		var pk int
+		if err := rows.Scan(&cid, &name, &columnType, &notNull, &defaultValue, &pk); err != nil {
+			return err
+		}
+		if name == column {
+			return rows.Err()
+		}
+	}
+	if err := rows.Err(); err != nil {
+		return err
+	}
+
+	_, err = s.db.Exec(fmt.Sprintf(`ALTER TABLE %s ADD COLUMN %s %s`, table, column, definition))
 	return err
 }