Add a standalone docking example for the dashboard dock-zone layout system

Context

The dashboard dock-zone layout system has shipped substantial machinery across ~15+ PRs — Neo.dashboard.DockZoneModel (the dock-zone document schema), Neo.dashboard.DockLayoutAdapter (projects a model → a container of hbox/vbox/tabs + splitter affordances + edge-zones), Neo.dashboard.DockSplitter (interactive resize), plus split-tab layouts (#13107), preview state (#13087), drag-preview affordances (#13109), the resizeSplit operation (#13160), splitter drag-wiring (#13225), named-layout helpers (#13175), pin state (#13168), persistence (#13152), and the src/-relocation of the model (#13142).

But there is no standalone example. The only consumer is apps/agentos/view/DockPreview.mjs — inside the early-PoC AgentOS app (slated for replacement by the Agent Harness, #13012). So the dock system has no isolated surface to demo, exercise, or visually verify independent of that app.

The Problem

A maturing, ~15-PR subsystem with no standalone example means:

• No showcase — nothing to point a human or agent at to see the dock / split / tab / resize behavior working.
• No isolated exercise surface — the only way to drive it is through the whole AgentOS app (heavy, and being replaced).
• No canonical reference — the model → DockLayoutAdapter.project → rendered container flow lives only in DockLayoutAdapter.spec.mjs (unit assertions) + the AgentOS view; a runnable example is the missing didactic + visual-verification surface.

The Architectural Reality

• examples/dashboard/ already exists — the standalone example belongs at examples/dashboard/dock/, mirroring the sibling example structure (index.html + app.mjs + a view/viewport).
• The example drives the public API directly: build a representative DockZoneModel document (the documented edge-zone root shape — center/right zones, split orientation + sizes, tab containers; see DockLayoutAdapter.spec.mjs), render it via DockLayoutAdapter.project(model, {resolveComponentRef}), and mount the resulting container.
• The interactive layer (DockSplitter resize, the resizeSplit operation, named-layout switching, pin, persist) is exercised by user interaction in the running example.

The Fix

A new standalone examples/dashboard/dock/ example app that:

1. Composes a representative dock-zone model (split + tabs + edge-zones over a few panels).
2. Renders it through DockLayoutAdapter into a live, mounted dashboard.
3. Demonstrates the shipped interactive features: splitter drag-resize, tab/split zones, and (where wired) named-layout switching + layout persistence + pin.

Acceptance Criteria

• A standalone example exists at examples/dashboard/dock/ (index.html + app.mjs + view), mirroring the existing examples/dashboard/ sibling structure + registered wherever Neo examples are indexed.
• It builds a representative DockZoneModel document (split + tab + edge-zone nodes over ≥3 panels) and renders it via DockLayoutAdapter.project.
• The interactive splitter drag-resize works in the running example (the resizeSplit path).
• At least one polish feature is demonstrated / toggleable: named-layout switching, layout persistence, or pin state (whichever are wired + demoable).
• No new dock feature code in src/dashboard/ — the example consumes the existing public API only (any defect surfaced is filed separately).

Out of Scope

• New docking features / behavior changes in src/dashboard/* — this is an example of the existing logic (any gap found is a separate ticket).
• The Agent Harness app itself (apps/ — #13012); this is a focused examples/ demo.
• Auto-hide / perspectives / grouped-drag if not yet shipped — those are #13158 polish leaves; the example demonstrates what exists.

Related

• Docking epic: #13158 (QT-parity docking polish). Strategies anchor: #13030 (dock/split/tab layouts).
• Dock machinery: src/dashboard/{DockZoneModel,DockLayoutAdapter,DockSplitter,Container,Panel}.mjs; API reference: test/playwright/unit/dashboard/DockLayoutAdapter.spec.mjs + DockSplitter.spec.mjs.
• Existing (non-standalone) consumer: apps/agentos/view/DockPreview.mjs.
• Surfaced by @tobiu (2026-06-14): many dock PRs landed, no standalone example.

Authored by @neo-opus-vega (Claude Opus 4.8, Claude Code). Origin Session ID: 4cc428e3-cf36-4324-8646-1b96cb23fa4a.