Update input/output shape

[alexandratran]

Source PR: Consensys-Incorporated/zesu#77

This PR updates Zesu to the glamsterdam-devnet v6.1.0 / zkevm v0.5.0 spec fixtures and implements the Amsterdam-fork EIP set. Two documentation-relevant surfaces changed:

1. Output commitment shape: a new 73-byte DEFAULT_FAILED_OUTPUT / canonical _default_failed_stateless_output is introduced for failed-execution/undecodable-input cases, and the commit length is now "variable" rather than the fixed 105 bytes currently documented.
2. SSZ input/ProtocolFork: ProtocolFork enum remapped and chain_config gains activation-related fields.

In docs/concepts/inputs-and-outputs.mdx

• update the "Output Commitment Structure" table (currently fixed 105 bytes) to cover the new 73-byte failed/sentinel-rejection output and variable commit length
• update chain_config field description for new activation fields.

[alexandratran]

Confirm with current source what the input/output shape is. The following new PR makes potentially superseding changes (failed
output is now 61 bytes, not 73).

New source PR: Consensys-Incorporated/zesu#81

This PR changes the SSZ input/output schema in ways that contradict what's currently published:

• Schema identifier: changed from a fixed 0x0001 prefix to fork_byte||0x01 (fork identity now derives from the prefix instead of
  from SszForkConfig).
• Output size reduced: successful output shrinks from 105 to 69 bytes; failed output shrinks from 73 to 61 bytes.
• SszForkConfig shrunk: fork and blob_schedule fields dropped, leaving only activation_offset — the chain_config trailer is now much smaller than documented.
• SszExecutionRequests expanded: grew from 3 to 5 fields (adds builder_deposits capped at 2^6 and builder_exits capped at 2^4 per EIP-8282), hash-tree-root leaf count grew from 4 to 8 chunks.

docs/concepts/inputs-and-outputs.mdx currently states the StatelessValidationResult is a "105-byte SSZ commitment" with a byte-layout table showing chain_config occupying [33..105] (72 bytes). Both the total size and the table are now stale. docs/reference/cli-options.mdx also repeats the "105-byte SSZ commitment" figure in its Output streams section.

[alexandratran]

Additional source PR: Consensys-Incorporated/zesu#86

This PR makes htExecutionRequests() (and the new_payload_request_root it feeds) fork-aware: pre-Amsterdam forks now use a 3-field/4-leaf merkle layout for execution requests (deposits/withdrawals/consolidations), while Amsterdam+ uses the 5-field/8-leaf layout (adding builder deposits/exits per EIP-8282). Also changes ssz_output.serialize() to take a chain_config struct instead of discrete chain_id/activation_timestamp scalars.

docs/concepts/inputs-and-outputs.mdx documents new_payload_request_root as "SSZ hash_tree_root of the NewPayloadRequest" and separately describes "typed execution requests (deposits, withdrawals, consolidations)" under
new_payload_request. The fork-dependent leaf-count behavior introduced here is new, doc-relevant information not currently captured — readers integrating pre-Amsterdam CL clients (Lighthouse/Prysm) need this to reproduce new_payload_request_root correctly.

[alexandratran]

Additional source PR: Consensys-Incorporated/zesu#96

• SszStatelessInput now embeds chain_id inline instead of nesting a ChainConfig struct, growing the fixed region from 16 to 20 bytes.
• The StatelessValidationResult output commitment is flattened from the previously documented 105-byte layout (root[0:32] || success[32] || ssz chain_config[33:105]) to a new 43-byte layout: root || valid || chain_id || schema_id.