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]>

docs/webui-local-dev.md

@@ -36,6 +36,8 @@ Optional environment variables:
 |------|-------------|
 | `/` | Home / operator overview |
 | `/health` | JSON liveness (`status`, `service`, `mode`, `timestamp`) |
+| `/queue` | Live PR and issue queue dashboard (#429) |
+| `/api/queue` | JSON queue export with pagination metadata |
 | `/projects` | Project registry list (#427) |
 | `/projects/{id}` | Project detail + onboarding checklist |
 | `/api/projects` | JSON registry export |
@@ -69,8 +71,19 @@ Prompts are generated at load time from canonical workflow files under
 copy/paste starters; canonical workflow files remain the only full policy
 source.
 
+## Live queue dashboard (#429)
+
+`/queue` loads open PRs and issues for the default registry project (seed:
+**Gitea-Tools** on `https://gitea.prgs.cc`) using existing `gitea_auth` read
+credentials. The UI surfaces pagination proof (returned count, pages fetched,
+`has_more`, `inventory_complete`) and classification badges (`claimed`,
+`blocked`, `in-review`, `duplicate`) when evidence exists.
+
+If credentials are missing or the fetch fails, the page shows an explicit error
+instead of an empty queue (fail closed).
+
 ## Tests
 
 ```bash
-pytest tests/test_webui_skeleton.py tests/test_webui_project_registry.py tests/test_webui_prompt_library.py -q
+pytest tests/test_webui_skeleton.py tests/test_webui_project_registry.py tests/test_webui_prompt_library.py tests/test_webui_queue_dashboard.py -q
 ```