Share constrained STM32 code while preserving firmware features

Omit unbound forwarding-region callbacks only for exclusive Companion source roles. Reuse the compact neighbor sorter in repeaters for every RPC order and the CLI list, removing duplicate sort implementations while preserving storage and size gates.

examples/simple_repeater/MyMesh.cpp

@@ -60,9 +60,10 @@ mesh::FloodAdvertLimiter::Entry* repeaterRtcAdvertSlowBank() {
 #endif
 #include <helpers/radiolib/RadioPowerLimits.h>
 #include <helpers/radiolib/RxBoostedGainDefaults.h>
+#include <helpers/SmallTableSort.h>
 #include <algorithm>
 #include <new>       // std::nothrow (heap-allocated flood rule table)
-#include <stdlib.h>  // for qsort()
+#include <stdlib.h>
 #include <helpers/CLICommandUtils.h>
 #include <helpers/FloodCommandAliases.h>
 #if defined(NRF52_POWER_MANAGEMENT)
@@ -707,7 +708,7 @@ void MyMesh::sendDefaultPasswordWarning(ClientInfo* client,
   }
 }
 
-// Comparison functions for qsort() - defined at file scope to avoid heap allocations
+// Shared neighbour ordering; equally ranked entries have no guaranteed tie order.
 static int cmp_neighbours_newest_to_oldest(const void* a, const void* b) {
   const NeighbourInfo* na = *(const NeighbourInfo**)a;
   const NeighbourInfo* nb = *(const NeighbourInfo**)b;
@@ -942,21 +943,20 @@ int MyMesh::handleRequest(ClientInfo *sender, uint32_t sender_timestamp, uint8_t
         }
       }
 
-      // Sort neighbours based on order using qsort() - standard C library function
-      // qsort() doesn't allocate heap memory (uses stack-based recursion) and is O(n log n)
-      // This matches the pattern used elsewhere in the codebase (e.g., BaseChatMesh)
+      // Share the bounded O(n log n) sorter instead of retaining separate C
+      // and C++ sort implementations on flash-constrained boards.
       if (order_by == 0) {
         // sort by newest to oldest
-        qsort(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*), cmp_neighbours_newest_to_oldest);
+        mesh::sortSmallTable(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*), cmp_neighbours_newest_to_oldest);
       } else if (order_by == 1) {
         // sort by oldest to newest
-        qsort(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*), cmp_neighbours_oldest_to_newest);
+        mesh::sortSmallTable(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*), cmp_neighbours_oldest_to_newest);
       } else if (order_by == 2) {
         // sort by strongest to weakest
-        qsort(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*), cmp_neighbours_strongest_to_weakest);
+        mesh::sortSmallTable(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*), cmp_neighbours_strongest_to_weakest);
       } else if (order_by == 3) {
         // sort by weakest to strongest
-        qsort(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*), cmp_neighbours_weakest_to_strongest);
+        mesh::sortSmallTable(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*), cmp_neighbours_weakest_to_strongest);
       }
 
       // build results buffer
@@ -6023,9 +6023,8 @@ void MyMesh::formatNeighborsReply(char *reply) {
   }
 
   // sort neighbours newest to oldest
-  std::sort(sorted_neighbours, sorted_neighbours + neighbours_count, [](const NeighbourInfo* a, const NeighbourInfo* b) {
-    return a->heard_timestamp > b->heard_timestamp; // desc
-  });
+  mesh::sortSmallTable(sorted_neighbours, neighbours_count, sizeof(NeighbourInfo*),
+                       cmp_neighbours_newest_to_oldest);
 
   for (int i = 0; i < neighbours_count && dp - reply < 134; i++) {
     NeighbourInfo *neighbour = sorted_neighbours[i];