Per-pack dashboard widgets #208

Context

The OpenRange dashboard is domain-agnostic — it shows the world
graph, builder lineage, and request log. That's the right baseline.
But each domain has a natural visualization the generic graph view
doesn't capture:

• Cyber: service topology + vuln chain + attack path
• Trading: order book depth + P&L curve + order timeline
• Robotics: 3D scene + trajectory + collision/contact events
• Social / negotiation: dialogue tree + intent graph

Asking the dashboard to know about each of these doesn't scale —
the dashboard would accumulate domain logic. The right move is
packs ship their own widgets.

What this issue tracks

Add a plugin point so packs can register pack-specific dashboard
widgets. The dashboard core renders the generic views; each
installed pack contributes its own panels.

Open design questions — design doc PR before code:

• Where does widget code live? In the pack package? A sibling
  package? Loaded as a JS bundle from the pack folder?
• How are widgets loaded? Entry point on the Python side
  (openrange.dashboard.widgets) that returns JS+CSS strings? Or
  bundled JS shipped alongside the pack?
• What's the data contract? Widgets need access to pack-defined
  state (graph nodes by type, request log filters, custom event
  streams). Define a stable widget API so widgets don't break on
  every dashboard refactor.

Why it matters

Without this, every new pack that lands either lives without
domain-shaped visualization (annoying) or pushes its UI logic into
core dashboard code (doesn't scale). Plugin point lets each pack
own its inspection surface.

Where to start

• src/openrange/dashboard/ — current dashboard package.
• src/openrange/core/pack.py — Pack ABC; the new hook would
  go alongside verifier_helpers / runtime_backings /
  default_builder.
• src/openrange/packs/cyber_webapp_offense_v1/codegen/discovery.py
  — the cyber discovery payload is what a cyber-specific widget
  would render.

Acceptance

• Design doc PR with the widget API + loading mechanism.
• Reference implementation: cyber pack ships a topology widget
  that visualizes the service graph + oracle path better than the
  generic view.
• Generic dashboard renders without the widget when no pack widgets
  are installed.

Notes

Don't design this in isolation. Ship the inspector improvements
(#206) first; if the resulting view is good enough that pack-specific
widgets aren't urgent, this issue can wait.