[eval] UI: eval scenario table

Part of #380
Depends on: #385

## What

SvelteKit page showing registered eval scenarios sourced from Scouter bifrost via OpsML proxy.

- Paginated table: scenario name, space, version, linked service, created date, status
- Inline editable fields (e.g. metadata/description)
- Proxy route in OpsML server: `GET /opsml/api/eval/scenarios` → Scouter bifrost
- Follows existing neo-brutalist table patterns in the UI
- Empty state for spaces with no registered scenarios

Start with the existing neo-brutalist table patterns in the SvelteKit UI and the OpsML server entry point for GET /opsml/api/eval/scenarios. Trace how registered eval scenarios are sourced from Scouter bifrost through the proxy. Done means the paginated scenario table, inline editing, linked service and status fields, and empty state are all supported.

Written by the indexing model from the issue text.