fix(spec-tests): align fork_choice test runner with Lodestar TS

- Fix attestation step: use force_import=false for step attestations
  (only block-body attestations use force_import=true, matching TS
  importAttestations: Force)
- Add importBlockAttestations to process block body attestations
  through fork choice after onBlock (mirrors pyspec is_from_block=True)
- Add pending_payload_statuses map to store execution engine mock
  statuses for consumption during block processing (mirrors TS
  ExecutionEngineMockBackend.addPredefinedPayloadStatus)
- Add getBlockExecutionStatus to look up stored payload status by
  execution payload block hash before defaulting to .valid
- Add validateBlobsProofs for deneb/electra blocks: validate that
  blobs and proofs counts match blobKzgCommitments (count-only,
  no KZG proof verification)
- Parse blobs/proofs fields from YAML block steps
- Handle multi-line should_override_forkchoice_update YAML values
- Add skip patterns in writer matching Lodestar TS skip list
- Bump spec test version to v1.7.0-alpha.2
- Add TODO for v1.7.0-alpha.1 proposer index check in onBlock

Author: GrapeBaBa

build.zig

@@ -25,7 +25,7 @@ pub fn build(b: *std.Build) void {
     const options_spec_test_options = b.addOptions();
     const option_spec_test_url = b.option([]const u8, "spec_test_url", "") orelse "https://github.com/ethereum/consensus-specs";
     options_spec_test_options.addOption([]const u8, "spec_test_url", option_spec_test_url);
-    const option_spec_test_version = b.option([]const u8, "spec_test_version", "") orelse "v1.6.0-beta.2";
+    const option_spec_test_version = b.option([]const u8, "spec_test_version", "") orelse "v1.7.0-alpha.2";
     options_spec_test_options.addOption([]const u8, "spec_test_version", option_spec_test_version);
     const option_spec_test_out_dir = b.option([]const u8, "spec_test_out_dir", "") orelse "test/spec/spec_tests";
     options_spec_test_options.addOption([]const u8, "spec_test_out_dir", option_spec_test_out_dir);

src/fork_choice/fork_choice.zig

@@ -474,6 +474,9 @@ pub const ForkChoice = struct {
         // (before attesting interval = before 1st interval).
         const is_timely = self.isBlockTimely(slot, block_delay_sec);
         // Only boost the first block we see.
+        // TODO GLOAS: v1.7.0-alpha.1 added proposer index check in update_proposer_boost_root
+        // (block.proposer_index == get_beacon_proposer_index(head_state)).
+        // Not yet implemented — matches Lodestar TS unstable.
         if (self.opts.proposer_boost and is_timely and self.proposer_boost_root == null) {
             self.proposer_boost_root = block_root;
         }