Establish and pilot the PortOS admin workspace design system

Start with docs/UX_DESIGN_GUIDE.md and docs/UX_DESIGN_AUDIT.md, then read child issues #7792–#7797 and the specification PR #7798. Confirm the specification prerequisite before reviewing each pilot. Done means the child acceptance criteria and bounded Settings, Brain and Apps audit are complete while preserving desktop/mobile navigation, existing routes and runtime behavior.

Design specification: PR #7798.

Problem / Goal

Rich admin pages mix configuration, setup, reference prose, tools and results in long documents, while horizontally overflowing and nested navigation hide useful destinations. Establish reusable task-focused workspace patterns and implement a bounded first rollout.

Reviewed design

The design-spec PR will add docs/UX_DESIGN_GUIDE.md and docs/UX_DESIGN_AUDIT.md, plus an entry in client conventions. Preserve icon-prefixed desktop navigation and the CoS-style mobile icon row. Grouped sheets may supplement discovery but must never replace fixed mobile icon navigation. The earlier text-only exploratory mockup is not the navigation contract.

Use six page families, desktop related-work/evidence columns, results-first information placement, short contextual explanations, named task views, existing drawers, and explicit asynchronous state. Keep URLs, provider-consent gates, saved-state behavior, model semantics and privacy intact.

Scope and sequence

1. Models navigation foundation, including cross-prefix hosts.
2. Jev task-view pilot.
3. Performance comparison/evidence pilot using the proven layout.
4. Runtimes operations roster and CoS queue-first task layout.
5. A bounded evidence-based Settings/Brain/Apps audit and linked follow-up backlog.

Implementation checklist:

• #7792 — Expose Models destinations in a grouped navigator while preserving desktop and mobile icons
• #7793 — Turn Jev into focused task views with side-by-side scoring and evidence
• #7794 — Make Model Performance results-first with focused test views and selected evidence
• #7795 — Reshape Runtimes around a consistent operations roster and selected configuration
• #7796 — Make CoS Tasks queue-first while retaining persona and icon navigation
• #7797 — Audit Settings, Brain and Apps against the adopted workspace patterns and file scoped follow-ups

This epic is a coordination item, not an implementation claim. Do not close it when the documentation PR merges.

Acceptance criteria

• The reviewed guide/audit are merged and linked from client conventions and docs index.
• Models navigation, Jev, Performance, Runtimes and CoS pilot issues meet their acceptance criteria.
• Desktop icons and mobile icon rows survive across all pilots, including keyboard/focus, names, selection and overflow behavior.
• Shared components are extracted only from proven repetition; current routes, aliases, runtime semantics and explicit provider actions remain compatible.
• Before/after task checks and responsive evidence use synthetic data and distinguish observed usability from hypotheses.
• The bounded follow-up audit produces concrete deduplicated work for Settings, Brain and Apps; it does not claim every PortOS page has been redesigned.

Delivery policy

Every child waits for the specification PR to merge. Further dependencies are explicitly identified as foundation or rollout sequencing; the blocked label is removed only after that child's prerequisites are met. Preserve readable dependency links in each child. No broad global CSS replacement, backend behavior change, or live-instance data in artifacts.