[eval] UI: eval scenario table

[thorrester]

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