feat: add live PR/issue queue dashboard to web UI (Closes #429)

Adds read-only /queue and /api/queue routes that load open PRs and issues
from the default registry project via gitea_auth, surface pagination proof,
and classify items with claimed/blocked/in-review/duplicate badges.

Co-Authored-By: Claude Opus 4.8 (1M context) <[email protected]>

webui/app.py

@@ -14,6 +14,8 @@ from webui.project_registry import find_project, load_registry, registry_to_dict
 from webui.project_views import render_project_detail, render_projects_list
 from webui.prompt_library import find_prompt, library_to_dict
 from webui.prompt_views import render_prompt_detail, render_prompts_page
+from webui.queue_loader import load_queue_snapshot, snapshot_to_dict
+from webui.queue_views import render_queue_page
 
 _READ_ONLY_METHODS = frozenset({"GET", "HEAD", "OPTIONS"})
 
@@ -32,6 +34,7 @@ async def home(_request: Request) -> HTMLResponse:
         "<h2>Operator console</h2>"
         "<p>Local entry point for MCP Control Plane operational views.</p>"
         "<ul>"
+        "<li><strong>Queue</strong> — live PR and issue dashboard (#429)</li>"
         "<li><strong>Projects</strong> — registry and onboarding (#427)</li>"
         "<li><strong>Prompts</strong> — canonical workflow prompt library (#428)</li>"
         "<li><strong>Runtime</strong> — MCP health and stale-runtime detection (#430)</li>"
@@ -52,6 +55,15 @@ async def health(_request: Request) -> JSONResponse:
     })
 
 
+async def queue(_request: Request) -> HTMLResponse:
+    snapshot = load_queue_snapshot()
+    return HTMLResponse(render_page(title="Queue", body_html=render_queue_page(snapshot)))
+
+
+async def api_queue(_request: Request) -> JSONResponse:
+    return JSONResponse(snapshot_to_dict(load_queue_snapshot()))
+
+
 async def projects(_request: Request) -> HTMLResponse:
     registry = load_registry()
     return HTMLResponse(render_projects_list(registry))
@@ -151,6 +163,8 @@ def create_app() -> Starlette:
         routes=[
             Route("/", home, methods=["GET"]),
             Route("/health", health, methods=["GET"]),
+            Route("/queue", queue, methods=["GET"]),
+            Route("/api/queue", api_queue, methods=["GET"]),
             Route("/projects", projects, methods=["GET"]),
             Route("/projects/{project_id}", project_detail, methods=["GET"]),
             Route("/api/projects", api_projects, methods=["GET"]),