## What this PR does
The SeaweedFS master's `/cluster/status` HTTP handler calls
`topo.Leader()`, which backs off exponentially up to
`MaxElapsedTime=20s` while the node has no leader in view. A 3-master
cluster bootstrap is a race: a master that briefly becomes the initial
raft leader and is then demoted can sit with an empty leader-view for a
while, so its `/cluster/status` takes up to ~20s to return (it does
return 200 — just slowly). The master liveness and readiness probes both
`httpGet /cluster/status:9333` with `timeoutSeconds: 10`, which is
shorter than that worst case. Such a master is liveness-killed roughly
every ~137s into a permanent CrashLoop (the master uses an `emptyDir`
data dir, so each container restart re-reads the same raft state and
re-wedges), and its readiness never succeeds — so the master StatefulSet
never reaches full readiness and the `seaweedfs-system` HelmRelease
install times out.
This raises both master probe `timeoutSeconds` to 30 (above the 20s
backoff) via the overlay values, deep-merging onto the subchart defaults
so only the timeout changes. Both probes must be raised: leaving
readiness at 10s would keep the master NotReady on the same slow
endpoint even if liveness no longer kills it. The volume component in
this same chart already uses a 30s probe timeout, so this aligns master
with that precedent. This is purely probe tuning — no raft, protocol, or
storage change.
The underlying upstream behavior (`/cluster/status` slow for a master
with an unhealthy raft view) is tracked upstream and is unchanged across
current SeaweedFS releases, so a version bump does not address it.
Switching the master to the Hashicorp raft backend is a separate, larger
change (it pulls in bootstrap and storage considerations) and is
intentionally out of scope here.
Operational note: on chart update each master StatefulSet rolls one pod
at a time with the new timeouts (raft quorum is preserved); a platform
upgrade therefore performs a short graceful roll of master pods on each
instance — not a data outage.
Adds a helm-unittest pinning both master probe timeouts and guarding
that the subchart's other probe fields survive the deep-merge.
### Release note
```release-note
fix(seaweedfs): raise the master liveness/readiness probe timeouts above the cluster-status leader-lookup backoff so a master with a transiently empty raft view is not killed into a permanent CrashLoop, which could time out the seaweedfs install
```
IvanHunters
2cb1b4c665