Marker presence was the launch gate, but the marker is provenance about who
ran the install -- not proof the runtime works. A CLI-installed repo+venv, or
a healthy install whose marker a repair deleted, both read as "never
installed" and dropped the user into first-run bootstrap on every launch.
Split the two questions: classifyActiveRuntime() reports marker validity and
runtime usability separately, and the resolver launches whenever the runtime
is usable, logging when it proceeds without a marker. An unusable runtime
still falls through to bootstrap even with a valid marker, so an interrupted
install can't spawn a dead backend.
Drops isBootstrapComplete(), which had no callers left once the gate moved.
Co-authored-by: iveywest <iveywest@users.noreply.github.com>
Co-authored-by: lihengming <lihengming@users.noreply.github.com>
