…#20835)

## Summary

`seg integrity` runs `CommitmentHistVal` and `StateRootVerifyByHistory`
regardless of whether commitment history is persisted on the datadir.
Both depend on commitment history `.v` files:

- `CheckCommitmentHistVal` iterates `.v` files; when none exist it
returns nil after logging `files=0`, which silently masks
misconfiguration as a passing check.
- `CheckCommitmentHistAtBlkRange` would fail confusingly when trying to
read history that isn't there.

This PR reads `rawdb.ReadDBCommitmentHistoryEnabled` once at the start
of `doIntegrity` and skips both checks with an informative log line when
the flag is off. Mirrors the existing `BorEvents` / `BorSpans`
chain-guard pattern in the same dispatch switch.

The other commitment checks (`CommitmentRoot`, `CommitmentKvi`,
`CommitmentKvDeref`, `StateVerify`) operate on the domain `.kv` files
and don't depend on history, so they remain unconditional.

## Test plan

- [x] `make lint` clean
- [x] `go build ./cmd/utils/app/...` succeeds
- [x] On a no-history datadir, run `seg integrity --check
CommitmentHistVal` and confirm the skip log appears and the command
exits 0 instead of "passing" with files=0
- [x] On a history-enabled datadir, confirm `CommitmentHistVal` and
`StateRootVerifyByHistory` still execute as before