Gloas: fix test failures (KZG verifier wiring, harness columns, WSS sync)

Brings the FORK_NAME=gloas beacon_chain test suite from 31 failures to green:

- v1 KZG batch verifier couldn't verify Gloas columns. Added
  verify_columns_against_block helper that picks commitments per fork
  (Fulu: inline on column; Gloas: signed_execution_payload_bid).
- BeaconChainHarness::process_envelope didn't persist columns. Now mirrors
  what production does in import_available_execution_payload_envelope.
- get_or_reconstruct_blobs returned an error for Gloas. Now short-circuits to
  Ok(None); WSS test copies columns from source to dest directly.
- update_data_column_signed_header (block_verification tests) only handled
  Fulu shape. Added a Gloas branch that re-keys to canonical_root.
- BlockError::EnvelopeBlockRootUnknown changed to tuple variant.
- Removed duplicate process_payload_envelope_availability.

beacon_node/beacon_chain/tests/block_verification.rs

@@ -323,18 +323,34 @@ fn update_data_column_signed_header<E: EthSpec>(
 ) {
     for old_custody_column_sidecar in data_columns.as_mut_slice() {
         let old_column_sidecar = old_custody_column_sidecar.as_data_column();
-        let new_column_sidecar = Arc::new(DataColumnSidecar::Fulu(DataColumnSidecarFulu {
-            index: *old_column_sidecar.index(),
-            column: old_column_sidecar.column().clone(),
-            kzg_commitments: old_column_sidecar.kzg_commitments().unwrap().clone(),
-            kzg_proofs: old_column_sidecar.kzg_proofs().clone(),
-            signed_block_header: signed_block.signed_block_header(),
-            kzg_commitments_inclusion_proof: signed_block
-                .message()
-                .body()
-                .kzg_commitments_merkle_proof()
-                .unwrap(),
-        }));
+        let new_column_sidecar = match old_column_sidecar.as_ref() {
+            DataColumnSidecar::Fulu(_) => {
+                Arc::new(DataColumnSidecar::Fulu(DataColumnSidecarFulu {
+                    index: *old_column_sidecar.index(),
+                    column: old_column_sidecar.column().clone(),
+                    kzg_commitments: old_column_sidecar.kzg_commitments().unwrap().clone(),
+                    kzg_proofs: old_column_sidecar.kzg_proofs().clone(),
+                    signed_block_header: signed_block.signed_block_header(),
+                    kzg_commitments_inclusion_proof: signed_block
+                        .message()
+                        .body()
+                        .kzg_commitments_merkle_proof()
+                        .unwrap(),
+                }))
+            }
+            // Gloas columns reference the block by `beacon_block_root` instead of holding the
+            // block header inline, so updating the parent root just means re-keying the column to
+            // the new canonical root.
+            DataColumnSidecar::Gloas(g) => {
+                Arc::new(DataColumnSidecar::Gloas(types::DataColumnSidecarGloas {
+                    index: g.index,
+                    column: g.column.clone(),
+                    kzg_proofs: g.kzg_proofs.clone(),
+                    slot: g.slot,
+                    beacon_block_root: signed_block.canonical_root(),
+                }))
+            }
+        };
         *old_custody_column_sidecar = CustodyDataColumn::from_asserted_custody(new_column_sidecar);
     }
 }