feat(tasks): add needs_human intervention flag (CUST-WP-0009)

- Migration b4c5d6e7f8a9: adds needs_human (bool) + intervention_note (text) to tasks
- API: needs_human filter on GET /tasks/; 422 if flagged without note
- 3 MCP tools: flag_for_human, clear_human_flag, list_human_interventions
- Dashboard: interventions.md with amber cards and "Mark done" button
- Policy router + workstream DoD policy (workstream-dod.md)
- Workstream lifecycle docs page + workplan CUST-WP-0010
- CLAUDE.md: add step 4 (run fix-consistency after workplan writes)
- consistency_check.py: promote C-11 unlinked tasks from INFO to WARN

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

dashboard/src/policy/workstream-dod.md

@@ -0,0 +1,92 @@
+---
+title: Workstream Definition of Done
+---
+
+```js
+const API = "http://127.0.0.1:8000";
+```
+
+```js
+import {marked} from "npm:marked";
+
+const _resp = await fetch(`${API}/policy/workstream-dod`);
+if (!_resp.ok) throw new Error(`Failed to load policy: ${_resp.status}`);
+const _policy = await _resp.json();
+```
+
+```js
+let _content = _policy.content;
+let _editing = false;
+
+const _root = display(html`<div></div>`);
+
+async function _save(text) {
+  const r = await fetch(`${API}/policy/workstream-dod`, {
+    method: "PUT",
+    headers: {"Content-Type": "application/json"},
+    body: JSON.stringify({content: text}),
+  });
+  if (!r.ok) throw new Error(`Save failed: ${r.status}`);
+  _content = text;
+}
+
+function _toolbar(...nodes) {
+  return html`<div style="display:flex;gap:0.5rem;margin-bottom:1rem">${nodes}</div>`;
+}
+
+function _btn(label, primary = false) {
+  return html`<button style="
+    padding:0.35rem 0.9rem;border-radius:4px;cursor:pointer;font-size:13px;
+    background:${primary ? "#1e293b" : "#f1f5f9"};
+    color:${primary ? "#f8fafc" : "#1e293b"};
+    border:1px solid ${primary ? "#1e293b" : "#cbd5e1"};
+  ">${label}</button>`;
+}
+
+function _render() {
+  _root.innerHTML = "";
+
+  if (_editing) {
+    const area = html`<textarea style="
+      width:100%;box-sizing:border-box;height:520px;
+      font-family:ui-monospace,monospace;font-size:13px;line-height:1.6;
+      padding:0.75rem;border:1px solid #cbd5e1;border-radius:4px;
+      background:#f8fafc;color:#1e293b;resize:vertical;
+    ">${_content}</textarea>`;
+
+    const saveBtn  = _btn("Save", true);
+    const cancelBtn = _btn("Cancel");
+
+    saveBtn.onclick = async () => {
+      saveBtn.disabled = true;
+      saveBtn.textContent = "Saving…";
+      try {
+        await _save(area.value);
+        _editing = false;
+        _render();
+      } catch (e) {
+        saveBtn.disabled = false;
+        saveBtn.textContent = "Save";
+        alert(e.message);
+      }
+    };
+
+    cancelBtn.onclick = () => { _editing = false; _render(); };
+
+    _root.append(_toolbar(saveBtn, cancelBtn), area);
+
+  } else {
+    const editBtn = _btn("Edit");
+    editBtn.onclick = () => { _editing = true; _render(); };
+
+    const body = html`<div style="
+      max-width:720px;line-height:1.7;
+    "></div>`;
+    body.innerHTML = marked.parse(_content);
+
+    _root.append(_toolbar(editBtn), body);
+  }
+}
+
+_render();
+```