Add per-workstream task counts to state summary and dashboard

API:
- WorkstreamWithTaskCounts schema extends WorkstreamRead with
  tasks_total/todo/in_progress/blocked/done fields
- /state/summary now includes these counts in open_workstreams via
  a single extra GROUP BY query (workstream_id, status)

Dashboard:
- Replace domain workstream-count bar with a horizontal stacked
  progress bar per workstream (done/in-progress/blocked/todo)
- Workstreams with no tasks show "no tasks yet" annotation
- Workstreams with tasks show "X/N done" label after the bar
- Sorted by domain then title so domains group naturally

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

dashboard/src/index.md

@@ -117,21 +117,55 @@ if (regs.length === 0) {
 ```js
 import * as Plot from "npm:@observablehq/plot";
 
-const wsData = (summary.topics ?? []).map(t => ({
-  domain: t.domain,
-  count: (t.workstreams ?? []).length,
-}));
+const topicById = Object.fromEntries((summary.topics ?? []).map(t => [t.id, t.domain]));
 
-display(Plot.plot({
-  x: {label: "Domain"},
-  y: {label: "Open workstreams", grid: true},
-  marks: [
-    Plot.barY(wsData, {x: "domain", y: "count", fill: "domain", tip: true}),
-    Plot.ruleY([0]),
-  ],
-  marginBottom: 80,
-  width: 700,
-}));
+const openWs = (summary.open_workstreams ?? []).map(w => ({
+  title: w.title,
+  domain: topicById[w.topic_id] ?? "unknown",
+  done:        w.tasks_done        ?? 0,
+  in_progress: w.tasks_in_progress ?? 0,
+  blocked:     w.tasks_blocked     ?? 0,
+  todo:        w.tasks_todo        ?? 0,
+  total:       w.tasks_total       ?? 0,
+})).sort((a, b) => a.domain.localeCompare(b.domain) || a.title.localeCompare(b.title));
+
+const statusOrder = ["done", "in progress", "blocked", "todo"];
+const statusColors = ["#4caf50", "steelblue", "#ff7043", "#e0e0e0"];
+
+const taskRows = openWs.flatMap(w => [
+  {label: w.title, domain: w.domain, status: "done",        count: w.done},
+  {label: w.title, domain: w.domain, status: "in progress", count: w.in_progress},
+  {label: w.title, domain: w.domain, status: "blocked",     count: w.blocked},
+  {label: w.title, domain: w.domain, status: "todo",        count: w.todo},
+]).filter(d => d.count > 0);
+
+if (openWs.length === 0) {
+  display(html`<p style="color:gray">No open workstreams.</p>`);
+} else {
+  display(Plot.plot({
+    y: {label: null, tickSize: 0, domain: openWs.map(w => w.title)},
+    x: {label: "Tasks", grid: true},
+    color: {domain: statusOrder, range: statusColors, legend: true},
+    marks: [
+      Plot.barX(taskRows, {y: "label", x: "count", fill: "status", tip: true}),
+      Plot.text(openWs.filter(w => w.total > 0), {
+        y: "title", x: "total",
+        text: d => ` ${d.done}/${d.total}`,
+        dx: 4, textAnchor: "start", fontSize: 11, fill: "gray",
+      }),
+      Plot.text(openWs.filter(w => w.total === 0), {
+        y: "title", x: 0,
+        text: () => " no tasks yet",
+        textAnchor: "start", fontSize: 11, fill: "#aaa",
+      }),
+      Plot.ruleX([0]),
+    ],
+    marginLeft: 200,
+    marginRight: 70,
+    height: Math.max(80, openWs.length * 44 + 50),
+    width: 700,
+  }));
+}
 ```
 
 ```js