touch: drop the V4 memory/store diagnostics + fix a swallowed hex escape

The RAM investigation and the language-download debugging left Serial probes
across three files: the BOOTMEM/MESHMEM/MEMPROBE macros and their 48 call
sites, plus the [STORE]/[APPCAT]/[LANGDL]/[LANGSEL] traces. They have served
their purpose and were flooding the companion USB-CDC, so they all go. Two
locals in the .lang installer (wr, wr3) existed only to feed a trace and go
with it; the control-write repair path that actually rebuilds /lang stays.

Separately, the map tile-cache help text read "256\xC3\x97256": the 256 after
the multiplication sign is all hex digits, so the compiler folded it into the
escape and emitted one out-of-range byte instead of "256x256". Breaking the
literal after the escape terminates it.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

src/MyMesh.cpp

@@ -3257,15 +3257,8 @@ void MyMesh::popChannelScope() {
   _chan_scope_pushed = false;
 }
 
-#define MESHMEM(tag) do { \
-    multi_heap_info_t _h{}; heap_caps_get_info(&_h, MALLOC_CAP_INTERNAL | MALLOC_CAP_8BIT); \
-    Serial.printf("[MESHMEM] %-12s free=%6u psram=%7u\n", tag, \
-                  (unsigned)_h.total_free_bytes, (unsigned)ESP.getFreePsram()); Serial.flush(); } while (0)
-
 void MyMesh::begin(bool has_display) {
-  MESHMEM("enter");
   BaseChatMesh::begin();
-  MESHMEM("post-base");
 
   if (!_store->loadMainIdentity(self_id)) {
     self_id = radio_new_identity(); // create new random identity
@@ -3288,9 +3281,7 @@ void MyMesh::begin(bool has_display) {
 #endif
 
   // load persisted prefs
-  MESHMEM("pre-prefs");
   _store->loadPrefs(_prefs, sensors.node_lat, sensors.node_lon);
-  MESHMEM("post-prefs");
 
   // sanitise bad pref values
   _prefs.rx_delay_base = constrain(_prefs.rx_delay_base, 0, 20.0f);
@@ -3332,13 +3323,10 @@ void MyMesh::begin(bool has_display) {
 #endif
 
   resetContacts();
-  MESHMEM("pre-contacts");
   _store->loadContacts(this);
-  MESHMEM("post-contacts");
   bootstrapRTCfromContacts();
   addChannel("Public", PUBLIC_GROUP_PSK); // pre-configure Andy's public channel
   _store->loadChannels(this);
-  MESHMEM("post-channels");
 
   applyRadioFromPrefs();   // freq/bw/sf/cr + TX power + RX-boost (shared with the live UI apply)
 #if defined(DISPLAY_CLASS)