feat(parity): real --info=del deletion lines + rsync throttle pacing

- Wire: config frame gains report_deletes (protocol 2.26.0 -> 2.27.0); the
  receiver lists actually-removed paths in the STATUS_STATS path list, so the
  sender prints rsync's `deleting PATH` / `*deleting   PATH` lines for a real
  --delete run (and -i/out-format).  Observers threaded through the manifest,
  missing-args and per-directory delete engines; golden wire len/hash updated.
- bwlimit: throttle now paces like rsync 3.4.1 -- ~100ms burst capacity and the
  sleep is no longer credited as refill, so 4 MiB at 1024/2048 KiB/s matches
  rsync within ~4% (was ~2x too fast).

src/server/server.c

@@ -956,8 +956,11 @@ void handler(int file_descriptor) {
          server-contacting --dry-run deletes nothing (no manifest is sent). */
       if (context->deferred_manifest) {
         size_t deleted = 0;
+        DeletePathObserver observer =
+            config->report_deletes ? receiver_record_deleted_path : NULL;
         DeleteCommitResult deletion =
-            manifest_delete_all_counted(config, context->deferred_manifest, &deleted);
+            manifest_delete_all_observed(config, context->deferred_manifest, &deleted, observer,
+                                         (void*)context->deleted_paths);
         context->stats.deleted_files += deleted;
         if (deletion == DELETE_COMMIT_ERROR) {
           transfer_ok = false;
@@ -975,6 +978,10 @@ void handler(int file_descriptor) {
       if (context->deferred_plans) {
         /* Defence in depth (the enclosing block already excludes dry-run): a
            -n run never commits a deletion. */
+        if (config->report_deletes)
+          delete_plan_session_set_delete_observer(context->deferred_plans,
+                                                  receiver_record_deleted_path,
+                                                  (void*)context->deleted_paths);
         DeleteCommitResult deletion =
             config->dry_run ? DELETE_COMMIT_OK
                             : delete_plan_session_commit(context->deferred_plans, config);
@@ -1010,7 +1017,7 @@ void handler(int file_descriptor) {
       /* Emit the optional wire-stats record first (protocol 2.25.0), then the
          success/outcome frame, exactly like the single-threaded receiver. */
       if (!receiver_send_stats_frame(file_descriptor, config, &context->stats,
-                                     context->would_delete) ||
+                                     context->would_delete, context->deleted_paths) ||
           !receiver_send_final_success(file_descriptor, config, &context->outcomes, final_status))
         transfer_ok = false;
     } else {