Issue #8: with timeout_s >= stall_window_s a single timed-out request
exhausted the stall window before the second attempt was even dispatched,
so LLM_MAX_RETRIES never applied and the whole scope was declared dead.
Root cause is that real attempts and non-productive waiting charged the
same wall clock, while the stall budget is the smaller of the two. The new
StallClock subtracts attempt time from the stall account, leaving the two
budgets orthogonal: attempts bill max_attempts, waiting bills
stall_window_s. The dual-condition verdict, the inf semantics of
progress_age_s, the 429 exemption and the error surface are untouched.
The productive boundary is _attempt itself, telemetry included, so a slow
recorder cannot push a call into a stalled verdict.
iomgaa
02c3d06ec6