Add TUI kanban board, review workflow, and new task statuses

Replace task statuses (pending/running/succeeded/failed/cancelled) with
a kanban workflow: todo → in_progress → in_review → done/wontdo.

When a non-review agent task completes, the API auto-creates a child
review task and moves the parent to in_review. Only humans can move
tasks from in_review to done/wontdo via the TUI.

New components:
- cmd/tui: bubbletea kanban board with $EDITOR integration
- POST /api/v1/tasks/{id}/complete: agent completion callback
- Operator --api-url flag for completion callbacks
- ProviderQueue sets tasks to in_progress on pickup
- AgentTask reconciler calls /complete on job finish

internal/controller/agenttask_controller.go

@@ -1,8 +1,11 @@
 package controller
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
+	"net/http"
 
 	batchv1 "k8s.io/api/batch/v1"
 	corev1 "k8s.io/api/core/v1"
@@ -13,11 +16,14 @@ import (
 	"sigs.k8s.io/controller-runtime/pkg/log"
 
 	forgebotv1alpha1 "git.unkin.net/unkin/forgebot/api/v1alpha1"
+	"git.unkin.net/unkin/forgebot/pkg/models"
 )
 
 type AgentTaskReconciler struct {
 	client.Client
-	Scheme *runtime.Scheme
+	Scheme     *runtime.Scheme
+	APIURL     string
+	HTTPClient *http.Client
 }
 
 // +kubebuilder:rbac:groups=forgebot.unkin.net,resources=agenttasks,verbs=get;list;watch;create;update;patch;delete
@@ -91,6 +97,7 @@ func (r *AgentTaskReconciler) handleRunning(ctx context.Context, task *forgebotv
 		if err := r.Status().Update(ctx, task); err != nil {
 			return ctrl.Result{}, err
 		}
+		r.completeAPITask(ctx, task, models.CompleteTaskRequest{})
 		logger.Info("task succeeded", "task", task.Name)
 		return ctrl.Result{}, nil
 	}
@@ -103,6 +110,7 @@ func (r *AgentTaskReconciler) handleRunning(ctx context.Context, task *forgebotv
 		if err := r.Status().Update(ctx, task); err != nil {
 			return ctrl.Result{}, err
 		}
+		r.completeAPITask(ctx, task, models.CompleteTaskRequest{ErrorMessage: "job failed"})
 		logger.Info("task failed", "task", task.Name)
 		return ctrl.Result{}, nil
 	}
@@ -178,6 +186,30 @@ func (r *AgentTaskReconciler) buildJob(task *forgebotv1alpha1.AgentTask, pool *f
 	}
 }
 
+func (r *AgentTaskReconciler) completeAPITask(ctx context.Context, task *forgebotv1alpha1.AgentTask, req models.CompleteTaskRequest) {
+	if r.APIURL == "" {
+		return
+	}
+	apiTaskID := task.Annotations["forgebot.unkin.net/api-task-id"]
+	if apiTaskID == "" {
+		return
+	}
+	logger := log.FromContext(ctx)
+
+	body, _ := json.Marshal(req)
+	httpReq, _ := http.NewRequestWithContext(ctx, http.MethodPost,
+		r.APIURL+"/api/v1/tasks/"+apiTaskID+"/complete", bytes.NewReader(body))
+	httpReq.Header.Set("Content-Type", "application/json")
+
+	httpClient := r.HTTPClient
+	if httpClient == nil {
+		httpClient = http.DefaultClient
+	}
+	if _, err := httpClient.Do(httpReq); err != nil {
+		logger.Error(err, "failed to complete API task", "apiTaskID", apiTaskID)
+	}
+}
+
 func (r *AgentTaskReconciler) SetupWithManager(mgr ctrl.Manager) error {
 	return ctrl.NewControllerManagedBy(mgr).
 		For(&forgebotv1alpha1.AgentTask{}).