docs: host-reboot drill + regression analysis for v0.71.0

Re-drilled the HOST reboot (felhom-pve) x2 after the follow-up challenge: both
recover all 8 drive-backed apps automatically; host-btime prefix advances so the
host path triggers processGuestBootChange; the boot-race manifests on host reboots
too (not just guest). Corrected the REPORT's 'host path unaffected' claim.

Regression analysis: the v0.68 sweep genuinely exercised the recovery (it surfaced
a real state-filter bug on the host reboot), so the agent path worked then and
regressed after (controller.yaml reset to golden no-local_api baseline on each
recreate; old MaybeIngest never re-merged). v0.70.0 config round-trip exonerated
(GET /api/config is verbatim). ensureLocalAPI closes the regression on both paths.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

CHANGELOG.md

@@ -40,7 +40,12 @@ Tests (non-hollow, with pre-fix companions, red-proofed): `pollLiveBinds` waits
 reports live (recreate fires) / never-live stays absent / a single early sample misses the not-yet-live
 bind; `ensureLocalAPI` merges `local_api` into an already-configured controller.yaml that lacks it
 (companion: pre-fix MaybeIngest left it empty) and no-ops when already present. Live-accepted with
-repeated `pct reboot 9201`.
+**guest reboots ×2 AND host (`felhom-pve`) reboots ×2** — all 8 drive-backed apps recover automatically,
+zero manual starts; the persisted boot-id now advances per boot (it had been frozen at the first-boot
+value). Note: the agent path worked at the v0.68 acceptance (it surfaced a real bug there) and regressed
+afterward — `controller.yaml` is reset to the golden's no-`local_api` baseline on each container recreate
+and the old `MaybeIngest` never re-merged it; `ensureLocalAPI` closes that. The boot-race manifests on
+host reboots too (not just guest), so both paths needed this fix.
 
 ### v0.70.0 — config-apply self-restart + geo-restriction UX fixes (2026-06-16)