feat(storage): paginate operations history with prev/next controls

Backend:
- ListStorageJobs(limit, offset) adds OFFSET for pagination
- CountStorageJobs() returns total row count for UI
- handler returns { jobs, total, limit, offset }
- JobManager.List(limit, offset) updated signature

Frontend:
- loadJobs(offset) with default 0
- Pagination UI: 'Mostrando X-Y de Z' + Anterior/Siguiente buttons
- After job start/end, reloads from offset 0
- listStorageJobs(limit, offset) API updated

Tests: fix List/ListStorageJobs calls to include offset=0

internal/db/queries_storage.go

@@ -159,13 +159,13 @@ func (d *DB) TrimJobOutput(id int64, maxLines int) error {
 	return nil
 }
 
-func (d *DB) ListStorageJobs(limit int) ([]StorageJob, error) {
+func (d *DB) ListStorageJobs(limit, offset int) ([]StorageJob, error) {
 	if limit <= 0 {
-		limit = 50
+		limit = 20
 	}
 	rows, err := d.conn.Query(`
 		SELECT id, kind, status, args_json, pid, started_at, finished_at, exit_code, output, error, created_at
-		FROM storage_jobs ORDER BY created_at DESC LIMIT ?`, limit)
+		FROM storage_jobs ORDER BY created_at DESC LIMIT ? OFFSET ?`, limit, offset)
 	if err != nil {
 		return nil, fmt.Errorf("list storage jobs: %w", err)
 	}
@@ -182,6 +182,15 @@ func (d *DB) ListStorageJobs(limit int) ([]StorageJob, error) {
 	return jobs, rows.Err()
 }
 
+func (d *DB) CountStorageJobs() (int, error) {
+	var count int
+	err := d.conn.QueryRow(`SELECT COUNT(1) FROM storage_jobs`).Scan(&count)
+	if err != nil {
+		return 0, fmt.Errorf("count storage jobs: %w", err)
+	}
+	return count, nil
+}
+
 func (d *DB) GetRunningJob() (*StorageJob, error) {
 	row := d.conn.QueryRow(`
 		SELECT id, kind, status, args_json, pid, started_at, finished_at, exit_code, output, error, created_at

internal/db/queries_storage_test.go

@@ -14,7 +14,7 @@ func TestListStorageJobsEmptyReturnsSlice(t *testing.T) {
 		t.Fatalf("migrate: %v", err)
 	}
 
-	jobs, err := d.ListStorageJobs(50)
+	jobs, err := d.ListStorageJobs(50, 0)
 	if err != nil {
 		t.Fatalf("ListStorageJobs: %v", err)
 	}

internal/storage/jobs.go

@@ -285,8 +285,8 @@ func (jm *JobManager) Get(id int64) (db.StorageJob, error) {
 	return jm.db.GetStorageJob(id)
 }
 
-func (jm *JobManager) List(limit int) ([]db.StorageJob, error) {
-	return jm.db.ListStorageJobs(limit)
+func (jm *JobManager) List(limit, offset int) ([]db.StorageJob, error) {
+	return jm.db.ListStorageJobs(limit, offset)
 }
 
 func (jm *JobManager) Cancel(id int64) error {

internal/storage/jobs_test.go

@@ -54,7 +54,7 @@ func TestJobManagerListEmpty(t *testing.T) {
 	defer d.Close()
 
 	jm := NewJobManager(d, false)
-	jobs, err := jm.List(10)
+	jobs, err := jm.List(10, 0)
 	if err != nil {
 		t.Fatalf("List: %v", err)
 	}
@@ -85,7 +85,7 @@ func TestJobManagerResetOrphans(t *testing.T) {
 		t.Fatalf("ResetOrphans: %v", err)
 	}
 
-	jobs, _ := jm.List(10)
+	jobs, _ := jm.List(10, 0)
 	runningCount := 0
 	queuedCount := 0
 	for _, j := range jobs {

internal/web/handlers_storage.go

@@ -111,14 +111,23 @@ func (s *Server) handleStorageUpdateConfig(w http.ResponseWriter, r *http.Reques
 func (s *Server) handleStorageListJobs(w http.ResponseWriter, r *http.Request) {
 	limit, _ := strconv.Atoi(r.URL.Query().Get("limit"))
 	if limit <= 0 {
-		limit = 50
+		limit = 20
 	}
-	jobs, err := s.JM.List(limit)
+	offset, _ := strconv.Atoi(r.URL.Query().Get("offset"))
+	if offset < 0 {
+		offset = 0
+	}
+	jobs, err := s.JM.List(limit, offset)
 	if err != nil {
 		writeError(w, http.StatusInternalServerError, err.Error())
 		return
 	}
-	writeJSON(w, http.StatusOK, map[string]any{"jobs": jobs})
+	total, err := s.DB.CountStorageJobs()
+	if err != nil {
+		writeError(w, http.StatusInternalServerError, err.Error())
+		return
+	}
+	writeJSON(w, http.StatusOK, map[string]any{"jobs": jobs, "total": total, "limit": limit, "offset": offset})
 }
 
 func (s *Server) handleStorageGetJob(w http.ResponseWriter, r *http.Request) {