Replace the readCell func(nibble int, skip bool) callback pattern with
direct data passing:

- New hph.hashRow(row, depth) feeds keccak2 and extracts [16]cellEncodeData
  in a single pass over the afterMap — no closure, no captured vars, no
  heap escapes from fmt.Printf in trace paths.
- EncodeBranch(bitmap, touchMap, afterMap, *[16]cellEncodeData) is now a
  pure serializer with no side effects.
- CollectUpdate takes *[16]cellEncodeData; nil/zero for delete cases,
  eliminating RetrieveCellNoop.
- createCellGetter and the readCell callback type are removed.

Benchmark (Benchmark_HexPatriciaHashed_Process, 10s):
  Before: 96208 ns/op  11121 B/op  113 allocs/op
  After:  99154 ns/op  10921 B/op  110 allocs/op
  Delta:  +3% ns (noise), -200 B/op (-1.8%), -3 allocs (-2.3%)

Co-authored-by: shuo <shuo@erigon.dev>

…ce check

When USE_STATE_CACHE is on, SharedDomains.GetLatest serves reads from
stateCache without re-verifying against the backing tx. Under suspected
cache invalidation bugs, a stale cache entry silently propagates into
gas accounting (observed: tx #27 in Sepolia block 10619150 under-charged
by 13680 gas).

Add an ASSERT_STATE_CACHE env flag that, on every stateCache hit, fetches
the authoritative value from the backing tx and panics on any divergence.
This makes the bug fail loudly at the exact offending (domain, key) instead
of silently flowing through execution.

Set ASSERT_STATE_CACHE=true alongside USE_STATE_CACHE=true to trip the
panic on first divergence; the panic message identifies the domain, key,
cached value, DB value and txNum.