…updates

The chat scroll position jumped every time the git watcher WebSocket
received data because urlTransform was recreated on every AgentDetail
render due to React Compiler hook interleaving, and isConnected state
caused unnecessary re-renders on every WebSocket lifecycle event.

Three changes fix this:

1. Extract buildUrlTransform as a module-level function and pass
   primitive fields (proxyHost, agentName, wsName, wsOwner) via
   urlTransformProps instead of a pre-built function. The compiler
   guards the props object on primitives (stable) and guards the
   buildUrlTransform call inside AgentDetailView (slot 5). The
   AgentDetailTimeline guard (slot 59) now hits when git data
   changes, keeping the scroll container content cached.

2. Convert isConnected from useState to useRef in useGitWatcher.
   No component renders this value; it was causing two wasted
   full-tree re-renders per WebSocket open/close cycle.

3. Split the gitWatcher prop into gitRepositories and gitRefresh,
   and use repositoriesRef for imperative access in
   handleOpenInEditor. This removes the opaque gitWatcher object
   from the AgentDetailView JSX guard, preventing unnecessary
   element re-creation when only git data changes.