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/tui/detail.go

@@ -0,0 +1,117 @@
+package tui
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/charmbracelet/bubbles/viewport"
+	"github.com/charmbracelet/lipgloss"
+
+	"git.unkin.net/unkin/forgebot/pkg/models"
+)
+
+type detailView struct {
+	task     *models.Task
+	viewport viewport.Model
+	ready    bool
+}
+
+func newDetailView() detailView {
+	return detailView{}
+}
+
+func (d *detailView) setTask(task *models.Task, width, height int) {
+	d.task = task
+	d.viewport = viewport.New(width, height-2)
+	d.viewport.SetContent(d.renderContent(width))
+	d.ready = true
+}
+
+func (d *detailView) renderContent(width int) string {
+	t := d.task
+	if t == nil {
+		return ""
+	}
+
+	var b strings.Builder
+
+	titleStyle := lipgloss.NewStyle().Bold(true).Foreground(statusColors[t.Status])
+	b.WriteString(titleStyle.Render(fmt.Sprintf("Task: %s", t.ID)))
+	b.WriteString("\n\n")
+
+	row := func(label, value string) {
+		b.WriteString(detailLabelStyle.Render(label))
+		b.WriteString(detailValueStyle.Render(value))
+		b.WriteString("\n")
+	}
+
+	row("Status:", string(t.Status))
+	row("Command:", t.Command)
+	row("Repository:", t.Repository)
+	row("Ref:", t.Ref)
+	row("Author:", t.Author)
+	if t.PoolRef != "" {
+		row("Pool:", t.PoolRef)
+	}
+	if t.IssueNumber > 0 {
+		row("Issue:", fmt.Sprintf("#%d", t.IssueNumber))
+	}
+	if t.PRNumber > 0 {
+		row("PR:", fmt.Sprintf("#%d", t.PRNumber))
+	}
+	if t.Skill != "" {
+		row("Skill:", t.Skill)
+	}
+	if t.JobName != "" {
+		row("Job:", t.JobName)
+	}
+	if t.ParentTaskID != "" {
+		row("Parent:", t.ParentTaskID)
+	}
+
+	b.WriteString("\n")
+	row("Created:", t.CreatedAt.Format("2006-01-02 15:04:05"))
+	if t.StartedAt != nil {
+		row("Started:", t.StartedAt.Format("2006-01-02 15:04:05"))
+	}
+	if t.CompletedAt != nil {
+		row("Completed:", t.CompletedAt.Format("2006-01-02 15:04:05"))
+	}
+
+	if t.Body != "" {
+		b.WriteString("\n")
+		b.WriteString(lipgloss.NewStyle().Bold(true).Render("Body:"))
+		b.WriteString("\n")
+		b.WriteString(t.Body)
+		b.WriteString("\n")
+	}
+
+	if t.Result != "" {
+		b.WriteString("\n")
+		b.WriteString(lipgloss.NewStyle().Bold(true).Render("Result:"))
+		b.WriteString("\n")
+		b.WriteString(t.Result)
+		b.WriteString("\n")
+	}
+
+	if t.ErrorMessage != "" {
+		b.WriteString("\n")
+		b.WriteString(errStyle.Bold(true).Render("Error:"))
+		b.WriteString("\n")
+		b.WriteString(errStyle.Render(t.ErrorMessage))
+		b.WriteString("\n")
+	}
+
+	return b.String()
+}
+
+func (d *detailView) view() string {
+	if !d.ready {
+		return ""
+	}
+
+	header := lipgloss.NewStyle().Bold(true).Render("Task Detail") +
+		"  " + helpStyle.Render("esc=back  e=edit  j/k=scroll")
+
+	return header + "\n" + d.viewport.View()
+}