feat(admin): configure Trino at the top of org settings

[benben]

Summary

• Put Trino configuration first in the org configuration card, with separate Select cell, Enable Trino, and Disable Trino actions.
• Require an explicit saved initial assignment before enabling. Preserve existing assignments and resource-group tiers, including while disabled.
• Reuse the authenticated, admin-only, audited enable/disable endpoints. No provisioning token is exposed to the browser.
• Keep other unsaved org fields untouched by Trino actions. Retain the lower Trino card for provisioning status and live query counts.

This does not implement warehouse moves, maintenance barriers, or Gateway routing. Disabling Trino remains asynchronous reconciliation, not proof that all work has drained.

Validation

• TDD: new top-of-configuration placement test failed before implementation, then passed.
• just ui-test: typecheck, 210 tests, and production build passed.
• just lint: passed with zero issues.
• Coverage includes read-only viewers, immutable assignments, saved selection before enable, preserved tier, pending/error states, ambiguous writes, unconfigured environments, registry-only unassigned recovery, request shapes, and unsaved general org fields.
• Independent agent review completed; no blocking findings. Added the review's registry-only regression cases.

UI-only change over existing backend endpoints. No live warehouse settings were changed during development.

[github-actions]

Test Impact Plan

Deterministic summary of how this PR changes tests, CI runners, and coverage-risk signals.

Summary

Area	Added	Changed	Deleted
Test files	0	0	0
E2E/journey files	0	0	0
Workflow files	0	0	0

Signals

• Test cases: +0 / -0
• Assertions: +0 / -0
• Skips or known failures added: 0
• Workflow continue-on-error added: 0
• Workflow path filters added: 0
• Test commands removed from justfile: 0
• E2E/journey retry lines added: 0

Coverage risk: neutral or increased

No coverage-reduction warnings detected.

[bill-ph]

Reviewed the admin UI changes for top-level Trino configuration, explicit initial cell selection, separate enable/disable actions, immutable assignments, viewer read-only behavior, and preservation of unsaved org fields. The UI remains scoped to the existing authenticated admin-only backend endpoints, and I found no P0 blocker requiring a code change. Current CI is still in progress.\n\n— Robo Bill