Fix operator view status and pane role registry mapping

[lisihao]

摘要

• 将 multi-task pane 的角色发现从固定四分屏标题推断，提升为 physical operator registry 优先
• 给 status-server 增加 operator fleet / role pool / pane overlay 可见性
• 抽出共享 pane_overlay_state，把 live overlay 与 stale scrollback 分离

变更边界

in-scope

• pane_role_pool.py 的 registry-based role mapping
• status-server.py 的 physical operator summary / warning breakdown / pane overlay awareness
• 共享 pane_overlay_state.py
• 对应回归测试

out-of-scope

• 不改 dispatch reconcile / pm_dispatch closeout 守卫
• 不改 runtime drift sticky / graph projection 主链
• 不处理原工作区其他并行 feature 脏改动

已验证

• python3 -m pytest -q harness/tests/control_plane/test-pane-role-pool.py harness/tests/test-status-server-physical-operators-summary.py
  • 8 passed
• python3 -m py_compile harness/lib/pane_role_pool.py harness/lib/pane_overlay_state.py harness/lib/symphony/status-server.py
  • 通过

堆叠关系

• base: codex/runtime-drift-writepath-fix
• 与 dispatch_pool 为并列后续分支，不互相依赖