Icon generation reported errors but returned success. Aggregate target
write and verification failures into exit 1, while processing later
targets. Keep rendering dependencies in the isolated build group.
A synchronous open error consumed a slot. Returning that slot alone
still let a deferred throw suppress an earlier callback and stall the
queue. Schedule queue draining outside completed callbacks and retain
the original exception.
Verified real clean-source generation and structural checks for all
35 targets, plus a real write failure through the Node/uv runner.
Native Windows child tests cover immediate and deferred open errors.
POSIX descriptor-limit cases are explicit skips here, not passes.
No signed package or native macOS acceptance is claimed.
4188301624