Connection search only exists on the Connections page, and changes the folder view #263

Symptom. The / search lives in the Connections folder header. Using it replaces the folder view with results, so the folder you were in is gone when you clear the search; and there is no way to find a connection from Sessions, Recordings, Reports, Admin or Tokens without going to Connections first.

Proposed fix. One global search component (static/search.js) on every page: a box in the brand row, a dim blurred overlay with the summary, Type and Folder facets and the results table, over an untouched folder view. Focus or / opens it and lists every connection the user can see; typing narrows it; Escape, the backdrop or opening a folder closes it. Connect from a result opens the client; opening a folder from another page navigates to Connections with #open=scope/path. The index is cached in sessionStorage and re-fetched only when the address-book version changes. Results show the folder display name over its key and are styled once in rustguac.css. Page modals must sit above the search box.

Fixed by feat/global-connection-search. Part of the #254 series. Depends on #253 (version endpoint) and the display-name issue.