feat(controller): populate TemporalCluster Status.Endpoints

[bmorton]

Background

The operator UI (#63) renders an Endpoints card (Frontend / UI / Metrics) from TemporalCluster.Status.Endpoints. The TemporalCluster controller never sets these fields (only the TemporalDevServer controller populates its own endpoints), so the card always shows — / — / —.

Ask

Populate TemporalCluster.Status.Endpoints (EndpointsStatus{Frontend, UI, Metrics}) in the cluster controller's status reconciliation, using the resolved service DNS names/ports (e.g. <name>-frontend.<namespace>.svc:7233).

Notes

• Until this lands, the UI hides empty endpoint rows (see UI follow-ups to feat(ui): read-only operator UI (topology & state overview) #63).
• Keep fields empty/omitted when a given endpoint isn't applicable.

Follow-up to #63.