fix(delete): match rsync deletion semantics (#290)

- Scope the --delete extras walk to directories synchronized by the
  transfer: add a synchronized-directory section to the delete manifest
  (protocol 2.23.0) so --files-from subsets no longer delete untransmitted
  paths outside listed directory subtrees (data-loss fix).
- Separate --max-size/--min-size prune protection from --delete-excluded so
  size-pruned source mirrors survive (rsync parity).
- Unlink extraneous destination symlinks instead of skipping them.
- Make --max-delete partial (delete up to N, skip the rest) and exit 25;
  accept negative values as unlimited.
- Draw --delete-missing-args deletions from the shared --max-delete budget.
- Honor --force during --delay-updates publication.

Add unit and integration regression tests; update the pinned config wire
golden and version strings for the 2.23.0 manifest/status additions.

src/shared/multiprocessing.c

@@ -30,6 +30,8 @@ PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* que
   context->max_queue_bytes = 0;
   context->manifest = NULL;
   context->excluded_paths = NULL;
+  context->size_skipped_paths = NULL;
+  context->synced_dirs = NULL;
   context->missing_args = NULL;
   context->scan_had_io_error = false;
   context->remove_source_files = NULL;
@@ -44,6 +46,7 @@ PipelineContextSender* pipeline_context_sender_create(Config* config, Queue* que
   protocol_session_set_max_alloc(&context->allocation_session, config->max_alloc);
   context->dir_entries = NULL;
   context->dir_entries_mutex_init = false;
+  context->delete_limit = false;
   int init = 0;
   if (config->use_metadata) {
     context->dir_entries = array_list_create(file_destroy);
@@ -186,6 +189,10 @@ void pipeline_context_sender_destroy(PipelineContextSender* context) {
   }
   if (context->excluded_paths)
     array_list_delete(context->excluded_paths);
+  if (context->size_skipped_paths)
+    array_list_delete(context->size_skipped_paths);
+  if (context->synced_dirs)
+    array_list_delete(context->synced_dirs);
   if (context->missing_args)
     array_list_delete(context->missing_args);
   if (context->remove_source_files)