test(parity): option-wave rsync differentials + docs (109/21/26)

- tests/integration/test_option_parity.py: bwlimit parse matrix + throttle
  rate, --info flist/name/nonreg/del(dry+real+itemize)/remove, real-setpriv
  --ignore-errors, rsync-daemon -M forwarding evidence, filter protect/risk
  destination-only divergence pin.
- RSYNC_COMPAT.md: tally 109/21/26; --bwlimit and --ignore-errors -> Parity,
  --filter and -M -> Divergent with differential rationale, --info residual
  narrowed to the categories with no client-observable event.
- HANDOFF/README: protocol 2.27.0, option-wave summary.

tests/test_multiprocessing.c

@@ -244,6 +244,7 @@ static void test_write_thread_done() {
    * and queue_destroy which would double-free since we created them
    * in this test. Let me just free the context directly. */
   array_list_delete(ctx->would_delete);
+  array_list_delete(ctx->deleted_paths);
   mtx_destroy(&ctx->mutex);
   cnd_destroy(&ctx->condition_not_full);
   cnd_destroy(&ctx->condition_not_empty);
@@ -329,6 +330,7 @@ static void test_receiver_enqueue_byte_budget() {
 
   /* Tear down: the second file is still queued and is freed by queue_destroy. */
   array_list_delete(ctx->would_delete);
+  array_list_delete(ctx->deleted_paths);
   mtx_destroy(&ctx->mutex);
   cnd_destroy(&ctx->condition_not_full);
   cnd_destroy(&ctx->condition_not_empty);