docs(steering): sync steering + xce-audit-invariants skill after Jul 13-18 work

- ha-async-io.md: document the same-batch endpoint lifetime hazard
  (bug-1447) and its ref-whole-batch-before-dispatch fix pattern
- xce-audit-invariants SKILL.md: add object-lifetime-within-a-dispatch-batch
  as a 6th audit dimension, so a future pass checks other batch loops
  (vtaskmgr drain, peer-list iteration) for the same shape
- product.md: replace the stale "HA consistency family is the current
  focus" framing with the actual 2026-07-18 status (umbrella complete,
  9-spec validate-impl batch closed, job-array-single-wal-record shipped)
- roadmap.md: correct 5 entries that were stale relative to actual spec
  status (ha-consistency-invariants/ha-wal-replication/libxce-failover
  pulled out of "In Flight", ha-term-safety and raft-drive-async marked
  implemented+GO, raft-sim-conformance and job-array-single-wal-record
  given closure annotations) -- struck through, not deleted, per this
  file's own additive-update convention
- testing.md: document that meson's aggregate Fail:0 can mask Unity
  sub-group failures -- always check the standalone binary's own summary
- src/controller/CLAUDE.md: fix a stale line-citation for the votedFor
  atomicity invariant (had drifted onto unrelated post-election code)

.kiro/steering/testing.md

@@ -75,6 +75,10 @@ extern void reset_ha_state(ha_state_t *s);
 
 **Add a test case in `testsuite/` before modifying any C implementation.**
 
+## Verifying a Test Run Actually Passed
+
+**Meson's aggregate `Ok:N Fail:0` is not sufficient evidence.** Meson can report a suite `Fail:0` while Unity sub-groups inside it fail — meson only tracks the process exit code of each *meson test unit*, not each Unity `RUN_TEST`. Always cross-check the **standalone test binary's own stdout** (`controller_unit_test`, `xcelib_test`, etc., run directly) for its authoritative `:FAIL:` count / `N Tests M Failures` summary before treating a run as green. This was the root cause of a masked-failure bug in the Unity harness itself (nested `UNITY_BEGIN()`/`UNITY_END()` across 83 `controller/testsuite/*.c` files swallowed the real exit code — fixed 2026-07-17) and is now the standard verification step for every `/kiro-validate-impl` pass.
+
 ## Coverage Targets
 
 - Go: 80% minimum on business logic (controllers, services, store)