GraphView exposed via pluginLib needs an "embedded" mode for use on detail pages

[danbruno101]

#6992 exposes GraphView through window.pluginLib.ResourceMap — thank you,
this unblocked embedding graphs in the kro plugin (headlamp-k8s/plugins,
kro 0.2.0-alpha). Using it on plugin detail pages surfaced a set of
behaviors that make sense for the full-page Map but are surprising for an
embedded section. Requesting an opt-in embedded mode (or props) that:

1. Controlled/uncontrolled selection without URL sync. GraphView reads
   and writes the page's ?node= and ?group= query params
   (useQueryParamsState), so an embedded graph mutates the host page's URL
   and participates in browser history. Two GraphViews on one page would
   fight over the same params. An embedded mode should keep selection in
   component state (or accept selectedNode/onNodeSelect props).
2. No global namespace-filter coupling. Mounting dispatches
   setNamespaceFilter([]) when the URL has no ?namespace=, resetting the
   user's app-wide namespace selection as a side effect of visiting any page
   that embeds a graph.
3. Sources isolation. defaultSources is appended to, not substituted
   for, all globally registered plugin sources; there is no way to render
   only the sources the caller passes. (Today the workaround is
   defaultNodeSelection + connected-component collapsing, plus id-matched
   first-wins dedupe.)
4. Hideable chrome. The namespace autocomplete, source picker, group-by
   chips, and filters cannot be hidden; an embedded section usually wants
   just the canvas (or a reduced toolbar).
5. Skip unneeded discovery. useGetAllSources() (cluster-wide CRD list,
   API discovery, VPA/Gateway probes) runs even when the caller passes
   defaultSources only.
6. Minor: GraphViewProps is not exported from the barrel, so plugin
   wrappers cannot type their pass-through props; and the lazy wrapper's
   Suspense fallback={null} causes a layout jump unless the caller
   reserves height.

Alternatively, exporting the lower-level pieces (GraphRenderer,
GraphSourceManager, applyGraphLayout, GraphNodeDetails) would let
plugins compose a bare renderer themselves.