refactor(coprocessor): replace parent: &span with span.in_scope()

The explicit `parent: &span` pattern on log macros bypasses the
OtelJsonFormat trace_id injection layer. Replace with `span.in_scope()`
which enters the span as the current context, allowing the formatting
layer to see it. Each usage is a synchronous log call with no .await
inside, so thread-jumping is not a concern.

Author: Eikix

coprocessor/fhevm-engine/sns-worker/src/executor.rs

@@ -341,10 +341,12 @@ pub async fn garbage_collect(pool: &PgPool, limit: u32) -> Result<(), ExecutionE
     cleanup_span.record("rows_affected", rows_affected as i64);
 
     if rows_affected > 0 {
-        info!(parent: &cleanup_span,
-            rows_affected = rows_affected,
-            "Cleaning up old ciphertexts128"
-        );
+        cleanup_span.in_scope(|| {
+            info!(
+                rows_affected = rows_affected,
+                "Cleaning up old ciphertexts128"
+            )
+        });
     }
 
     Ok(())

coprocessor/fhevm-engine/transaction-sender/src/ops/verify_proof.rs

@@ -292,15 +292,19 @@ where
 
             let txn_request = match row.verified {
                 Some(true) => {
-                    info!(parent: &span, zk_proof_id = row.zk_proof_id, "Processing verified proof");
+                    span.in_scope(|| {
+                        info!(zk_proof_id = row.zk_proof_id, "Processing verified proof")
+                    });
                     let handles = row
                         .handles
                         .ok_or(anyhow::anyhow!("handles field is None"))?;
                     if handles.len() % 32 != 0 {
-                        error!(parent: &span,
-                            handles_len = handles.len(),
-                            "Bad handles field, len is not divisible by 32"
-                        );
+                        span.in_scope(|| {
+                            error!(
+                                handles_len = handles.len(),
+                                "Bad handles field, len is not divisible by 32"
+                            )
+                        });
                         self.remove_proof_by_id(row.zk_proof_id)
                             .instrument(span.clone())
                             .await?;
@@ -364,7 +368,9 @@ where
                     }
                 }
                 Some(false) => {
-                    info!(parent: &span, zk_proof_id = row.zk_proof_id, "Processing rejected proof");
+                    span.in_scope(|| {
+                        info!(zk_proof_id = row.zk_proof_id, "Processing rejected proof")
+                    });
                     if let Some(gas) = self.gas {
                         (
                             row.zk_proof_id,
@@ -389,10 +395,12 @@ where
                     }
                 }
                 None => {
-                    error!(parent: &span,
-                        zk_proof_id = row.zk_proof_id,
-                        "verified field is unexpectedly None for proof"
-                    );
+                    span.in_scope(|| {
+                        error!(
+                            zk_proof_id = row.zk_proof_id,
+                            "verified field is unexpectedly None for proof"
+                        )
+                    });
                     continue;
                 }
             };