Implements mode-aware event echo classification, job-arrival range
compression (Req 4.5), and round-collapse flush wiring at all 3
breakpoint-match/structural-event call sites (Requirements 1.1-1.4,
3.5, 3.6). All 4 of task 3.1's tests pass; also closes bug-1609
("continue is as verbose as step").
repl_break.c grew 827->905 lines (13% over the 800-line cap). Unlike
task 2.2's Round Rollup, this logic is wiring inside pre-existing
driver-facing hooks, not a relocatable subsystem - accepted in place
per design.md's established residual-tolerance precedent.
Review independently investigated a one-off ASAN stack-use-after-return
in an unrelated test (sched_sim_record_output_test) surfaced by this
change's stack-layout perturbation: traced to the same documented
pre-existing thread-lifecycle bug class as bug-1598/bug-1632 (an
unjoined picker thread reading a stack-local sim after test-function
return), confirmed via 11/11 clean reruns - logged as bug-1763, not a
regression from this task.
Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01YAWMhfRJFnmmnG8h97yUDd
Rongsong Shen
cc78d09140