refactor(ui)!: consolidate management console components

[halfofning]

Summary

• consolidate Agent, Kubernetes, and virtual-machine navigation, capability administration, chat presentation, issue ledgers, capability inventories, and install instructions behind shared managed-subject components
• standardize settings rows, password fields, telemetry facts/charts, workflow execution facts, responsive ledgers, and destructive automation dialogs while preserving domain adapters and routes
• migrate all remaining OverflowActionMenu consumers to ActionMenu, remove the obsolete UI-package export, and include the required breaking Changesets entry
• refresh seven reviewed Agent and cluster-settings visual baselines and keep the completed execution plans current

Cross-Repo Change Set

Tracking issue: none; this is a single-repository refactor.

Related PRs:

• acornops/management-console: this PR

Merge order:

1. management-console

Breaking Change

OverflowActionMenu is no longer exported from @acornops/ui. Consumers must use ActionMenu. A major Changesets entry is included.

Validation

• PASS: npm run validate — 206 test files and 1,001 tests; UI package checks, type checks, membership/contracts/harness checks, production build, route smoke, and bundle budget all passed
• PASS: npm run design:snapshots — 25 passed, 1 intentional platform-specific skip
• PASS: design-route coverage — all unchanged matrices passed; seven intentional Agent and cluster-settings baselines were reviewed, refreshed, and passed focused light/dark desktop/mobile reruns
• PASS: full fixture inventory — all 127 checks completed across bounded shards; the environment terminated the monolithic runner at its process boundary after its first 62 completed checks
• PASS: npm run smoke:mcp-parity — 8 passed
• PASS: targeted cluster/VM overview and catalog accessibility coverage — 11 passed
• PASS: targeted sidebar/navigation coverage — 5 Vitest checks and the collapsed-rail browser fixture passed
• PASS: npm run lint, npm run harness:check, and git diff --check
• INFO: npx impeccable detect --json --fast src packages/ui/src retains one pre-existing parser warning for the documented mono-font expression in src/styles.css

Docs Impact

• added and completed the managed-subject and component-dedup execution plans
• updated the completed-plan index and design-system adoption record
• added the UI package breaking-change note

Residual Risk

• downstream @acornops/ui consumers must migrate from OverflowActionMenu to ActionMenu
• browser runs continue to report the repository's existing stale caniuse-lite notice
• no API, permission, route, or cross-repository contract changes are included