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)

src/controller/CLAUDE.md

@@ -95,7 +95,7 @@ The `RequestVoteReply` message already carries `peerConfigTag` and `peerLastLogL
 ### Protocol Verification Checklist
 
 When modifying HA protocol code (election, replication, heartbeat), verify:
-- [ ] `votedFor` is updated atomically with term increment before granting any vote
+- [ ] `votedFor` is updated atomically with term increment before granting any vote (library: `raft_on_vote_request`, `src/lib/raft/raft.c:178-270` — term update before persist, `voted_for` set only after persist succeeds; adapter: `raft_cb_persist`, `ha.c:1784-1824`, writes term+voted_for atomically under `ha->lock`. `handle_request_vote` in `ha.c` is `#ifdef XCE_TESTING`-only; production dispatch is `cluster.c:477` → `raft_on_vote_request`. Corrected 2026-07-18 — the prior `ha.c:1218-1230` citation had drifted onto unrelated post-election code.)
 - [ ] `currentTerm` is monotonic — never decreases
 - [ ] `commitIndex` never decreases (monotonic)
 - [ ] A leader only commits entries from its current term (or equivalent via per-entry majority ack)