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/model/model.go

@@ -48,6 +48,9 @@ type ActionResult struct {
 
 type RunSummary struct {
 	StartedAt    time.Time      `json:"started_at"`
+	Status       string         `json:"status"`
+	ErrorStep    string         `json:"error_step,omitempty"`
+	ErrorMessage string         `json:"error_message,omitempty"`
 	DryRun       bool           `json:"dry_run"`
 	TotalRisk    int            `json:"total_risk"`
 	Matched      int            `json:"matched"`
@@ -65,6 +68,9 @@ type StatusCount struct {
 
 type RunRecord struct {
 	StartedAt    string `json:"started_at"`
+	Status       string `json:"status"`
+	ErrorStep    string `json:"error_step,omitempty"`
+	ErrorMessage string `json:"error_message,omitempty"`
 	DryRun       bool   `json:"dry_run"`
 	TotalRisk    int    `json:"total_risk"`
 	Matched      int    `json:"matched"`