chore: strip audit-ticket prefixes from code comments

Drops the ~60 ticket-prefix comments (CRIT-N, HIGH-N, MED-N, LOW-N,
L-N, M-N, AUDIT-N, PLUTUS-N, "audit fix (date):", "Phase N" labels,
"Adversarial-review fix:") that had accumulated in inline + doc
comments over several audit cycles. Where the surrounding prose
still carried useful WHY context it gets kept and tightened; where
the ticket WAS the comment it gets dropped entirely.

No logic, no renames, no behavior change. Audit history lives in
commit messages and the audits/ tree where it belongs — eternal
comments don't need to mirror it.

Net 138 LOC shorter. 253 tests pass, no new clippy or fmt warnings.

crates/aldabra-chain/src/koios.rs

@@ -527,10 +527,9 @@ mod tests {
         );
     }
 
-    // (the deserializes_tx_info_response / deserializes_empty_tx_info_response
-    // tests were dropped along with KoiosTxInfo when AUDIT4-1 swapped tx_status
-    // from /tx_info to /tx_status. Coverage is now in
-    // parses_koios_tx_status_shapes below.)
+    // tx_info-shape tests were dropped when tx_status moved from
+    // /tx_info to /tx_status. Coverage is in parses_koios_tx_status_shapes
+    // below.
 
     #[test]
     fn tx_status_serializes_with_tag() {