Migrate remaining in-repo workstream REST callers to /workplans

Point cleanup_stale_tasks, validate_repo_adr, custodian_cli, dashboard data
loaders, extensions poll, MCP legacy resource, and consistency_check task
queries at preferred /workplans routes. Add caller inventory evidence doc.

dashboard/src/data/workstreams.json.py

@@ -8,7 +8,7 @@ import urllib.error
 API_BASE = os.environ.get("API_BASE", "http://127.0.0.1:8000").rstrip("/")
 
 try:
-    with urllib.request.urlopen(f"{API_BASE}/workstreams", timeout=10) as resp:
+    with urllib.request.urlopen(f"{API_BASE}/workplans", timeout=10) as resp:
         data = json.loads(resp.read())
     print(json.dumps(data))
 except urllib.error.URLError as e:

dashboard/src/data/workstreams/[id].json.py

@@ -15,7 +15,7 @@ if not ws_id:
     sys.exit(1)
 
 try:
-    with urllib.request.urlopen(f"{API_BASE}/workstreams/{ws_id}", timeout=10) as resp:
+    with urllib.request.urlopen(f"{API_BASE}/workplans/{ws_id}", timeout=10) as resp:
         data = json.loads(resp.read())
     print(json.dumps(data))
 except urllib.error.HTTPError as e:

dashboard/src/extensions.md

@@ -14,7 +14,7 @@ const epState = (async function*() {
     try {
       const [re, rw, rt, rr] = await Promise.all([
         apiFetch("/extension-points/"),
-        apiFetch("/workstreams/"),
+        apiFetch("/workplans/"),
         apiFetch("/topics/"),
         apiFetch("/repos/"),
       ]);