Add MemAudit: per-subsystem heap accounting in the boot log (#10900)

* Add MemAudit: per-subsystem heap accounting in the boot log

The 2.8.0 nRF52840 heap-exhaustion field reports had to be diagnosed by
hand, reconstructing each subsystem's heap footprint from source and
build flags one report at a time. This makes every future report
self-diagnosing from the serial log: a tiny fixed-size registry
(src/memory/MemAudit.*) that big long-lived allocations report into,
printed as one line at the end of setup() and alongside the periodic
"Heap free:" log:

  MemAudit[boot]: tmm=2500 warm=4000 pkthist=5824 nodedb=13440
  msgstore=2200 pktpool(live)=3270 total=31234

Instrumented: NodeDB hot vector (nodedb) + satellite maps (satmaps,
rb-tree overhead estimated), WarmNodeStore (warm), PacketHistory records
and hash index (pkthist), TrafficManagement caches (tmm/tmm_ni),
MessageStore text pool (msgstore), TFT line/repaint buffers (display),
and live in-flight packets (pktpool(live)) via an optional audit tag on
the packet pool allocator - the one hot path, counted with a relaxed
32-bit atomic add (single instructions on Cortex-M, no locks).

Cost: 128 B RAM for the 16-tag table, well under 1 KB flash on rak4631.
MESHTASTIC_MEM_AUDIT=0 compiles it out to inline no-op stubs (call
sites need no ifdefs); STM32WL, the tightest flash target, defaults off.

New native suite test_mem_audit covers add/set/snapshot arithmetic, tag
reuse (pointer and cross-TU strcmp fallback), null/unknown tags, and
table-full behavior; test/native-suite-count bumped to 28.

* native-wasm: add src/memory/ to the curated source filter

The wasm env denies all sources and adds an explicit file list; MemAudit
callers (main, MeshService, NodeDB, PacketHistory) are in that list but
src/memory/MemAudit.cpp was not, so wasm-ld failed on undefined
memaudit:: symbols.

src/mesh/NodeDB.cpp

@@ -22,6 +22,7 @@
 #include "TypeConversions.h"
 #include "error.h"
 #include "main.h"
+#include "memory/MemAudit.h"
 #include "mesh-pb-constants.h"
 #include "mesh/generated/meshtastic/deviceonly_legacy.pb.h"
 #include "meshUtils.h"
@@ -1796,6 +1797,25 @@ bool NodeDB::enforceSatelliteCaps()
 #endif
 
     (void)trim; // all four maps may be compiled out
+
+    // Approximate satellite heap usage: each std::map entry is one rb-tree node,
+    // value_type plus ~44 B of node overhead (parent/left/right pointers, color,
+    // allocator rounding on 32-bit targets - an estimate, not exact bookkeeping).
+    size_t satBytes = 0;
+#if !MESHTASTIC_EXCLUDE_POSITIONDB
+    satBytes += nodePositions.size() * (sizeof(decltype(nodePositions)::value_type) + 44);
+#endif
+#if !MESHTASTIC_EXCLUDE_TELEMETRYDB
+    satBytes += nodeTelemetry.size() * (sizeof(decltype(nodeTelemetry)::value_type) + 44);
+#endif
+#if !MESHTASTIC_EXCLUDE_ENVIRONMENTDB
+    satBytes += nodeEnvironment.size() * (sizeof(decltype(nodeEnvironment)::value_type) + 44);
+#endif
+#if !MESHTASTIC_EXCLUDE_STATUSDB
+    satBytes += nodeStatus.size() * (sizeof(decltype(nodeStatus)::value_type) + 44);
+#endif
+    memaudit::set("satmaps", satBytes);
+
     return trimmedAny;
 }
 
@@ -2080,6 +2100,7 @@ void NodeDB::nodeDBSelfCare()
     // Normalise the backing store to the hot cap so getOrCreateMeshNode always
     // has spare slots to append into (it indexes meshNodes->at(numMeshNodes++)).
     meshNodes->resize(MAX_NUM_NODES);
+    memaudit::set("nodedb", MAX_NUM_NODES * sizeof(meshtastic_NodeInfoLite));
 
     const bool satsTrimmed = enforceSatelliteCaps();