perf(common): filter pushthrough optimization for decode param filter

crates/core/common/src/context/session_state.rs

@@ -124,13 +124,21 @@ impl SessionState {
 
     /// Applies DataFusion logical optimizations to an existing plan.
     ///
+    /// Runs custom pre-optimisation rewrites (filter pushthrough for
+    /// `evm_decode`) before delegating to DataFusion's standard optimizer.
+    /// This ensures derived predicates participate in predicate pushdown.
+    ///
     /// Does not trigger SQL pre-resolution; the plan is assumed to be fully
     /// resolved already.
     ///
     /// Mirrors [`DfSessionState::optimize`] (synchronous).
     #[tracing::instrument(skip_all, err)]
     pub fn optimize(&self, plan: &LogicalPlan) -> Result<LogicalPlan, DataFusionError> {
-        self.state.optimize(plan)
+        let plan = {
+            let _span = tracing::debug_span!("filter_pushthrough_decode").entered();
+            crate::filter_pushthrough_decode::filter_pushthrough_decode(plan.clone())?
+        };
+        self.state.optimize(&plan)
     }
 
     /// Returns a new `SessionState` with async catalog pre-resolution