fix(webui): remediate PR #856 REQUEST_CHANGES for policy visibility (#646)

Address review blockers (review #555):
- Graduate /policy nav item out of STUB_PAGES to live nav in webui/nav.py
- Update docs/webui-local-dev.md to list /policy as a live surface and remove stub copy
- Run console_redaction on HTML emit path in webui/policy_views.py before rendering HTML
- Add planted-secret HTML redaction test and nav graduation test in tests/test_webui_policy_visibility.py

webui/nav.py

@@ -60,7 +60,7 @@ NAV_GROUPS: tuple[NavGroup, ...] = (
         NavItem("/timeline", "Timeline", "stub"),
     )),
     NavGroup("Policy", (
-        NavItem("/policy", "Policy", "stub"),
+        NavItem("/policy", "Policy"),
         NavItem("/prompts", "Prompts"),
     )),
     NavGroup("Insights", (
@@ -88,10 +88,6 @@ STUB_PAGES: dict[str, tuple[str, str]] = {
         "Timeline",
         "Workflow event timeline across issues and PRs. A later Phase 1 surface.",
     ),
-    "/policy": (
-        "Policy",
-        "Capability and role policy surface. Placeholder until a later phase.",
-    ),
     "/insights": (
         "Insights",
         "Aggregate operational insights and trends. Placeholder until a later "