A corrupt nested repository can be discovered (its .git entry exists)
but fail its status probe. The stale-selection recovery cleared the
pick and forced a re-scan, and auto-select immediately re-picked the
same path, looping discovery walk + probe for as long as the surface
stayed visible.
clearNestedRepoSelection now remembers the dropped repository per root
(session-only set, cleared on runtime switch), and auto-select skips
remembered paths. When every candidate has failed, no selection is made
and surfaces settle into their unresolved state instead of churning
requests. A manual picker pick remains possible and is probed like any
other.