v0.2.0

First production feedback (#1): a run
against a small production engine with 8 hosts and an FC data domain.

Added

• host_health_rca findings for a failed guest-agent call carry vmCandidates: the VMs the
  engine reports on that host, as {vms, returned, limit, truncated, total, scanTruncated, error}. The event names no VM, so these are candidates to check — the tool description, the
  agent guardrails and the CLI ("VM candidates (not confirmed)") all say so. This adds one
  /vms read to the diagnosis, made once and only when such a finding exists; a VM list that
  cannot be read (a restricted account) is reported as error with total: null, never as a
  host running nothing, and does not fail the diagnosis. scanTruncated says the VM scan
  itself was cut at 1000, which makes total a lower bound. When the read failed there is no
  scan to describe, so truncated and scanTruncated are null rather than false. The
  envelope's limit is fixed; for the whole list on a busy host, read vm_list with
  search="host=<name>".
• The over-commit finding's signal carries actual use next to the commitment
  (committed 192.0% of capacity, in use 43.7% (56.3% free)).

Fixed

• A failed guest-agent call is no longer reported as a host fault. Event 10802
  (VDS_BROKER_COMMAND_FAILURE) wraps one vdsm command, and the engine logs it against the
  host that ran the call: VmLogonVDS failed: Guest agent non-responsive was ranked high
  under the generic "The engine logged a problem for this host" while the host was up,
  externalStatus: ok, with nothing pending. A VmLogon / VmLogoff command whose message
  names the guest agent is now low, says the host itself is not at fault, and is not
  superseded by the host's own recovery. The same command failing for another reason (a vdsm
  transport timeout, say) is about the host's link to vdsm and stays a host finding, as does
  every other vdsm command failure.
• Event 10802 is now grouped per condition — the command, plus whether the message names the
  guest agent — instead of per code. It wraps every vdsm command, so one group per host and
  code let the newest member classify the rest: a SpmStatusVDS failure followed by a
  guest-agent one was reported as the guest-agent finding, and its text appeared nowhere in
  the payload. The command alone is not enough either, because one command reports both
  conditions: a VmLogonVDS transport timeout must not be collapsed into a newer
  VmLogonVDS guest-agent failure.
• The over-commit cause no longer claims free space is "within the domain's own thresholds"
  when the engine set none. It reports 0 for a domain with no low-space warning, and 0 can
  never be crossed; the finding now says no check was made and points at the free space in
  its own signal.
• The over-commit finding now says which of two things it is: a planning limit while free
  space holds, or — together with a low-space finding — a promise that cannot be kept.
• The low-space action quoted a threshold the engine had not reported as None GiB.