feat(graph): compact kanban columns + column headers

- Empty columns no longer reserve space — only non-empty columns render
- Active columns are packed tightly next to each other
- Each column gets a header label (Todo, In Progress, Done, Review, Approved)
  with status color and subtle underline
- Columns centered under owner node

packages/agent-graph/src/canvas/draw-tasks.ts

@@ -8,6 +8,7 @@ import { COLORS, getTaskStatusColor, getReviewStateColor } from '../constants/co
 import { TASK_PILL, MIN_VISIBLE_OPACITY, ANIM } from '../constants/canvas-constants';
 import { truncateText } from './draw-misc';
 import { hexWithAlpha } from './render-cache';
+import type { KanbanZoneInfo } from '../layout/kanbanLayout';
 
 /**
  * Draw all task nodes as pill-shaped cards.
@@ -176,3 +177,30 @@ function drawTaskPill(
 
   ctx.restore();
 }
+
+/**
+ * Draw kanban column headers above task columns.
+ */
+export function drawColumnHeaders(
+  ctx: CanvasRenderingContext2D,
+  zones: KanbanZoneInfo[],
+): void {
+  for (const zone of zones) {
+    for (const header of zone.headers) {
+      ctx.font = 'bold 8px monospace';
+      ctx.textAlign = 'center';
+      ctx.textBaseline = 'bottom';
+      ctx.fillStyle = hexWithAlpha(header.color, 0.6);
+      ctx.fillText(header.label, header.x, header.y - 2);
+
+      // Subtle underline
+      const labelWidth = ctx.measureText(header.label).width;
+      ctx.beginPath();
+      ctx.moveTo(header.x - labelWidth / 2, header.y);
+      ctx.lineTo(header.x + labelWidth / 2, header.y);
+      ctx.strokeStyle = hexWithAlpha(header.color, 0.2);
+      ctx.lineWidth = 0.5;
+      ctx.stroke();
+    }
+  }
+}

packages/agent-graph/src/layout/kanbanLayout.ts

@@ -1,8 +1,8 @@
 /**
  * KanbanLayoutEngine — positions task nodes in kanban columns relative to their owner.
  *
- * Each member/lead gets a zone below them with 4 columns: todo → wip → review → done.
- * Tasks are pinned (fx/fy) — no d3-force drift. Deterministic layout.
+ * Each member/lead gets a zone below them with columns for non-empty statuses only.
+ * Empty columns are skipped — no wasted space. Each column has a header label.
  *
  * Class with ES #private methods, single source of truth from KANBAN_ZONE constants.
  */
@@ -10,6 +10,31 @@
 import type { GraphNode } from '../ports/types';
 import { KANBAN_ZONE } from '../constants/canvas-constants';
 
+/** Column header info for rendering */
+export interface KanbanColumnHeader {
+  label: string;
+  x: number;
+  y: number;
+  color: string;
+}
+
+/** Zone info per owner for rendering headers */
+export interface KanbanZoneInfo {
+  ownerId: string;
+  ownerX: number;
+  ownerY: number;
+  headers: KanbanColumnHeader[];
+}
+
+// Column display config
+const COLUMN_LABELS: Record<string, { label: string; color: string }> = {
+  todo: { label: 'Todo', color: '#6b7280' },
+  wip: { label: 'In Progress', color: '#3b82f6' },
+  done: { label: 'Done', color: '#22c55e' },
+  review: { label: 'Review', color: '#f59e0b' },
+  approved: { label: 'Approved', color: '#22c55e' },
+};
+
 export class KanbanLayoutEngine {
   // Reusable collections (cleared each call, never GC'd)
   static readonly #nodeMap = new Map<string, GraphNode>();
@@ -17,6 +42,9 @@ export class KanbanLayoutEngine {
   static readonly #unassigned: GraphNode[] = [];
   static readonly #colTasks = new Map<string, GraphNode[]>();
 
+  /** Zone info for rendering column headers — updated each layout() call */
+  static zones: KanbanZoneInfo[] = [];
+
   /**
    * Position all task nodes in kanban columns relative to their owner.
    * Call AFTER d3-force settles member positions, BEFORE drawing.
@@ -26,7 +54,6 @@ export class KanbanLayoutEngine {
     nodeMap.clear();
     for (const n of nodes) nodeMap.set(n.id, n);
 
-    // Group tasks by owner — reuse maps
     const tasksByOwner = this.#tasksByOwner;
     tasksByOwner.clear();
     const unassigned = this.#unassigned;
@@ -46,26 +73,27 @@ export class KanbanLayoutEngine {
       }
     }
 
-    // Layout each owner's tasks in kanban columns
+    // Reset zones
+    this.zones = [];
+
     for (const [ownerId, tasks] of tasksByOwner) {
       const owner = nodeMap.get(ownerId);
       if (!owner || owner.x == null || owner.y == null) continue;
-      KanbanLayoutEngine.#layoutZone(tasks, owner.x, owner.y);
+      const zoneInfo = KanbanLayoutEngine.#layoutZone(tasks, owner.x, owner.y, ownerId);
+      if (zoneInfo) this.zones.push(zoneInfo);
     }
 
-    // Unassigned tasks: separate zone
     KanbanLayoutEngine.#layoutUnassigned(unassigned);
   }
 
   // ─── Private ──────────────────────────────────────────────────────────────
 
-  static #layoutZone(tasks: GraphNode[], ownerX: number, ownerY: number): void {
+  static #layoutZone(tasks: GraphNode[], ownerX: number, ownerY: number, ownerId: string): KanbanZoneInfo | null {
     const { columnWidth, rowHeight, offsetY, columns, maxVisibleRows } = KANBAN_ZONE;
-    const totalWidth = columns.length * columnWidth;
-    const baseX = ownerX - totalWidth / 2;
+    const headerHeight = 20; // space for column header label
     const baseY = ownerY + offsetY;
 
-    // Classify each task into a column — reuse shared Map
+    // Classify tasks into columns
     const colTasks = KanbanLayoutEngine.#colTasks;
     colTasks.clear();
     for (const col of columns) colTasks.set(col, []);
@@ -75,21 +103,47 @@ export class KanbanLayoutEngine {
       colTasks.get(col)?.push(task);
     }
 
-    // Position each task in its column + row
-    for (const [colIdx, colName] of columns.entries()) {
-      const colNodes = colTasks.get(colName) ?? [];
-      for (const [rowIdx, task] of colNodes.entries()) {
+    // Collect only NON-EMPTY columns (skip empty — no wasted space)
+    const activeColumns: { name: string; tasks: GraphNode[] }[] = [];
+    for (const colName of columns) {
+      const nodes = colTasks.get(colName) ?? [];
+      if (nodes.length > 0) {
+        activeColumns.push({ name: colName, tasks: nodes });
+      }
+    }
+
+    if (activeColumns.length === 0) return null;
+
+    // Center active columns under owner
+    const totalWidth = activeColumns.length * columnWidth;
+    const baseX = ownerX - totalWidth / 2;
+
+    // Build headers + position tasks
+    const headers: KanbanColumnHeader[] = [];
+
+    for (const [colIdx, col] of activeColumns.entries()) {
+      const colX = baseX + colIdx * columnWidth;
+      const config = COLUMN_LABELS[col.name] ?? { label: col.name, color: '#888' };
+
+      // Column header
+      headers.push({
+        label: config.label,
+        x: colX + columnWidth / 2, // centered in column
+        y: baseY,
+        color: config.color,
+      });
+
+      // Position tasks below header
+      for (const [rowIdx, task] of col.tasks.entries()) {
         if (rowIdx >= maxVisibleRows) {
-          // Hide overflow tasks off-screen
           task.x = -99999;
           task.y = -99999;
           task.fx = task.x;
           task.fy = task.y;
           continue;
         }
-        const targetX = baseX + colIdx * columnWidth;
-        const targetY = baseY + rowIdx * rowHeight;
-        // Smooth slide: LERP toward target; instant on first appearance
+        const targetX = colX;
+        const targetY = baseY + headerHeight + rowIdx * rowHeight;
         task.x = task.x != null ? task.x + (targetX - task.x) * 0.15 : targetX;
         task.y = task.y != null ? task.y + (targetY - task.y) * 0.15 : targetY;
         task.fx = task.x;
@@ -98,17 +152,12 @@ export class KanbanLayoutEngine {
         task.vy = 0;
       }
     }
+
+    return { ownerId, ownerX, ownerY, headers };
   }
 
-  /**
-   * Determine which kanban column a task belongs to.
-   * Columns: todo → wip → done → review → approved
-   * approved is separate from review — approved goes after review.
-   */
   static #resolveColumn(task: GraphNode): string {
-    // Approved = separate column (after review)
     if (task.reviewState === 'approved') return 'approved';
-    // Active review/needsFix = review column (next to done)
     if (task.reviewState === 'review' || task.reviewState === 'needsFix') return 'review';
     switch (task.taskStatus) {
       case 'in_progress':

packages/agent-graph/src/ui/GraphCanvas.tsx

@@ -12,10 +12,11 @@ import { drawBackground, createDepthParticles, updateDepthParticles, type DepthP
 import { drawEdges } from '../canvas/draw-edges';
 import { drawParticles } from '../canvas/draw-particles';
 import { drawAgents } from '../canvas/draw-agents';
-import { drawTasks } from '../canvas/draw-tasks';
+import { drawTasks, drawColumnHeaders } from '../canvas/draw-tasks';
 import { drawProcesses } from '../canvas/draw-processes';
 import { drawEffects, type VisualEffect } from '../canvas/draw-effects';
 import { BloomRenderer } from '../canvas/bloom-renderer';
+import { KanbanLayoutEngine } from '../layout/kanbanLayout';
 import type { CameraTransform } from '../hooks/useGraphCamera';
 
 // ─── Draw State (passed by ref, not by props — no React re-renders) ─────────
@@ -208,6 +209,7 @@ export const GraphCanvas = forwardRef<GraphCanvasHandle, GraphCanvasProps>(funct
 
       // 2c. Visible nodes only (back to front: process → task → member/lead)
       drawProcesses(ctx, visibleNodes, state.time, state.selectedNodeId, state.hoveredNodeId);
+      drawColumnHeaders(ctx, KanbanLayoutEngine.zones);
       drawTasks(ctx, visibleNodes, state.time, state.selectedNodeId, state.hoveredNodeId);
       drawAgents(ctx, visibleNodes, state.time, state.selectedNodeId, state.hoveredNodeId);