The previous daemon's dead shutdown drain (an uncaught exception in a
shutdown thread) never passes through the logger, so it never carries an
ERROR/SEVERE token, so redeploy-fleetd.sh's existing ERROR-count classifier
is structurally blind to it and prints a confident "no ERROR lines since
restart" while the drain actually died.
Add scan_uncaught_exceptions (greps the shutdown window for the failure's
real shape: `Exception in thread`, `NoClassDefFoundError`) and
find_drain_complete_line (checks for #522's SessionManager.drainAll
completion line). Compose both in report_shutdown_drain, a single
decision+action function the main flow calls unconditionally (same shape
as swap_if_built/refuse_drain_gate from #521/#528), which resolves to one
of four outcomes: complete, died, unknown ("cannot tell" — the line is
absent for either of two reasons that need opposite handling: the previous
daemon predates #522, or its drain failed without throwing), or n/a (no
previous daemon was actually stopped this run). Never fails the redeploy;
warns loudly instead.
Gate the "no ERROR lines since restart" summary line on the new outcome so
it never reads as reassurance when the drain died or the outcome is
"cannot tell" (item 4 of the ticket).
Tests: 11 new test functions (60 defined/invoked, was 49), covering both
pure classifiers, all four report_shutdown_drain outcomes, a source-grep
proof of the main-flow call site (sourcing stops before the main flow
runs), an ordering check, and the item-4 gating. Full suite green
(exit 0, 0 anchored FAIL lines). Five mutations applied and killed by hand
during review, each restored to a byte-identical file afterward.
Dai Ha