40bfac268d
After upgrade kexec into v1.13.2, CM5 eMMC takes ~2m13s between the SDHCI controller registering and mmc0 actually becoming usable. The Talos config acquire state machine (`acquire.go::stateDisk`) checks STATE in the first seconds of boot, sees `VolumePhaseMissing`, and transitions one-way to `stateEmbedded` -> `stateMaintenanceEnter`. When STATE later becomes ready, the state machine doesn't re-enter `stateDisk`, so the node stays in maintenance forever despite the on-disk config.yaml being intact. This patch makes stateDisk tolerate transient phase=missing for up to 5 minutes (stateMissingDiskTimeout) before falling through to embedded. A 5-second ticker on the outer Run loop ensures the timeout can fire even when no further volume-status events arrive (e.g. truly missing STATE on a fresh install). Validated 2026-05-25 via canonical 3-CP rolling upgrade on a freshly flashed v1.12.4 home-test cluster: all 3 blades upgraded sequentially to v1.13.2-7 (this patch), each came back stage=running with config loaded automatically and k8s Ready within ~5 min, no manual remediation. See doc-compute-blade-kubernetes/talos-upgrade-validation/session-2026-05-25/E2E-VALIDATED.md. Fast-init hardware sees no change — STATE reaches ready within seconds and the existing path runs.