fix(realtime): only increase gas for bridge/UserOp txs, not anchor

The anchor tx has a required gas limit enforced by the L2 engine.
Revert anchor to 1M, keep processMessage and UserOp txs at 3M.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: smartprogrammer93

realtime/src/l2/execution_layer.rs

@@ -103,7 +103,7 @@ impl L2ExecutionLayer {
         let call_builder = self
             .anchor
             .anchorV4WithSignalSlots(anchor_block_params.0, anchor_block_params.1)
-            .gas(3_000_000)
+            .gas(1_000_000)
             .max_fee_per_gas(u128::from(l2_slot_info.base_fee()))
             .max_priority_fee_per_gas(0)
             .nonce(nonce)