feat: show todo progress in Herdr sidebar

tests/ui.test.ts

@@ -122,7 +122,11 @@ test("selects the most specific in-progress task and compresses parallel leaves"
     { name: "Parallel", description: "Parallel", status: "in-progress" },
   ]);
   assert.equal(currentTaskLabel(state.list()), "#2 Child +1");
-  assert.deepEqual(currentTaskTokens(state.list()), { task: "#2 Child", task_count: "+1" });
+  assert.deepEqual(currentTaskTokens(state.list()), {
+    task: "#2 Child",
+    task_count: "+1",
+    task_progress: "0/3",
+  });
 });
 
 test("uses blocked tasks only when nothing is in progress", () => {
@@ -132,10 +136,26 @@ test("uses blocked tasks only when nothing is in progress", () => {
     { name: "Blocked two", description: "Two", status: "blocked" },
   ]);
   assert.equal(currentTaskLabel(state.list()), "#1 Blocked one +1");
-  assert.deepEqual(currentTaskTokens(state.list()), { task: "#1 Blocked one", task_count: "+1" });
+  assert.deepEqual(currentTaskTokens(state.list()), {
+    task: "#1 Blocked one",
+    task_count: "+1",
+    task_progress: "0/2",
+  });
   state.update([{ id: 1, status: "done" }, { id: 2, status: "done" }]);
   assert.equal(currentTaskLabel(state.list()), null);
-  assert.deepEqual(currentTaskTokens(state.list()), { task: null, task_count: null });
+  assert.deepEqual(currentTaskTokens(state.list()), {
+    task: null,
+    task_count: null,
+    task_progress: "2/2",
+  });
+});
+
+test("clears sidebar progress for an empty task tree", () => {
+  assert.deepEqual(currentTaskTokens([]), {
+    task: null,
+    task_count: null,
+    task_progress: null,
+  });
 });
 
 test("hides an empty widget and renders a populated one", () => {