_profile_home deliberately raises for an explicit target that no longer exists
(an unavailable target must never fall back to the launch profile). Nothing
translated that exception, so a desktop client still holding a deleted profile
turned every profile-scoped RPC (session.create/resume, config.get/set, ...)
into "ws dispatch crash" + -32603. Raise a typed ProfileUnavailableError
(FileNotFoundError subclass, so method-level contracts are unchanged) and map
it once in handle_request to code 4064 — the code the other profile-scoped
surfaces already use for "profile not found". The display-only
_response_profile_name fall-back from #107831 now catches the typed error.
Folds the salvaged test into the existing target-unavailable file (one
invariant test covering both methods and the display helper). Fixes#107829.
teknium1
105e27f962