hub v0.1.7: Infrastructure backup endpoints for disaster recovery

Add infra-backup push/pull API for controller DR:
- POST /api/v1/infra-backup — controller pushes infrastructure snapshot
- GET /api/v1/infra-backup/{customer_id} — fresh controller pulls backup
- infra_backups SQLite table with per-customer snapshots
- Customer detail page shows infra backup status card
- README.md with full API docs and DR flow

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

hub/internal/store/store.go

@@ -91,6 +91,12 @@ func (s *Store) migrate() error {
 
 		CREATE INDEX IF NOT EXISTS idx_notification_log_customer
 			ON notification_log(customer_id, created_at DESC);
+
+		CREATE TABLE IF NOT EXISTS infra_backups (
+			customer_id TEXT PRIMARY KEY,
+			backup_json TEXT NOT NULL,
+			updated_at  DATETIME NOT NULL DEFAULT (datetime('now'))
+		);
 	`)
 	return err
 }
@@ -380,6 +386,75 @@ func (s *Store) GetCustomerHistory(customerID string, since time.Duration) ([]Cu
 	return history, rows.Err()
 }
 
+// SaveInfraBackup upserts the infrastructure backup for a customer.
+func (s *Store) SaveInfraBackup(customerID string, backupJSON []byte) error {
+	_, err := s.db.Exec(`
+		INSERT INTO infra_backups (customer_id, backup_json, updated_at)
+		VALUES (?, ?, datetime('now'))
+		ON CONFLICT(customer_id) DO UPDATE SET
+			backup_json = excluded.backup_json,
+			updated_at = datetime('now')`,
+		customerID, string(backupJSON),
+	)
+	return err
+}
+
+// GetInfraBackup returns the raw infra backup JSON for a customer, or nil if not found.
+func (s *Store) GetInfraBackup(customerID string) ([]byte, error) {
+	var data string
+	err := s.db.QueryRow(
+		"SELECT backup_json FROM infra_backups WHERE customer_id = ?",
+		customerID,
+	).Scan(&data)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+	return []byte(data), nil
+}
+
+// InfraBackupMeta holds summary info for the dashboard (avoids parsing full JSON).
+type InfraBackupMeta struct {
+	UpdatedAt  time.Time
+	StackCount int
+	DiskCount  int
+}
+
+// GetInfraBackupMeta returns summary metadata for a customer's infra backup.
+func (s *Store) GetInfraBackupMeta(customerID string) (*InfraBackupMeta, error) {
+	var backupJSON, updatedAt string
+	err := s.db.QueryRow(
+		"SELECT backup_json, updated_at FROM infra_backups WHERE customer_id = ?",
+		customerID,
+	).Scan(&backupJSON, &updatedAt)
+	if err == sql.ErrNoRows {
+		return nil, nil
+	}
+	if err != nil {
+		return nil, err
+	}
+
+	meta := &InfraBackupMeta{
+		UpdatedAt: parseSQLiteTime(updatedAt),
+	}
+
+	// Parse just the fields we need
+	var parsed struct {
+		DeployedStacks []json.RawMessage `json:"deployed_stacks"`
+		DiskLayout     struct {
+			Mounts []json.RawMessage `json:"mounts"`
+		} `json:"disk_layout"`
+	}
+	if json.Unmarshal([]byte(backupJSON), &parsed) == nil {
+		meta.StackCount = len(parsed.DeployedStacks)
+		meta.DiskCount = len(parsed.DiskLayout.Mounts)
+	}
+
+	return meta, nil
+}
+
 // Prune deletes reports older than the given number of days.
 func (s *Store) Prune(maxDays int) (int64, error) {
 	cutoff := time.Now().AddDate(0, 0, -maxDays).Format("2006-01-02 15:04:05")