feat: graft pyxis onto upstream microReticulum 0.4.1

Repins microReticulum + microLXMF onto the upstream-0.4.1 graft and adapts
pyxis to the new src/microReticulum/ layout and 0.4.x APIs. The far-diverged
0.3.0 fork's Resource/Transport/Identity work is subsumed by upstream's
reimplementation; only the still-needed fixes ride on the pinned branches
(PKCS7/HMAC/X25519 crypto -- proven byte-identical to python RNS 1.3.1 --
Packet link-proof callback, Identity short-sig guard, and the bz2 layer +
decompress-on-receive in Resource::assemble()).

Consumer-side changes:
- platformio.ini: pin microReticulum @2f21fee (pyxis-fixes-on-0.4.1) and
  microLXMF @33760d0 (chore/microreticulum-0.4.1-layout); bump microStore
  ceea8f5 -> c5fb69d (0.4.x requires the new BasicFileStore::init API);
  -std=gnu++11 -> gnu++17 (upstream requires C++17).
- Namespace all microReticulum includes (angle + quote) to <microReticulum/...>
  for the relocated layout; shim-local Utilities/Stream.h|Print.h preserved.
- Interface::send_outgoing now returns bool: update TCP/BLE/SX1262/Auto
  overrides with correct success/failure returns.
- SDArchiveFileSystem::init(bool reformatOnFail=true) to match new microStore.
- Static Transport::get_path_table() -> path_table(); instance getter unchanged.
- Remove duplicate shim Cryptography/BZ2 (microReticulum provides it now; keep
  lib/libbz2 as the ESP32 bzlib provider).
- patch_littlefs_paths.py: normalize microStore's LittleFS adapter paths to a
  leading "/" -- ESP32 Arduino LittleFS rejects "./"-prefixed paths, which
  silently broke the path store (no peer paths learned, all messaging blocked).

Validated on T-Deck Plus: builds (RAM 27.5% / Flash 77.7%), boots stable
(no WDT/panic), and a full on-device LXMF e2e (DIRECT + OPPORTUNISTIC +
bz2-compressed-Resource receive) passes 5/5.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01UWZuYkHBRqNb6BZHV8sTG5

lib/auto_interface/AutoInterface.cpp

@@ -1,6 +1,6 @@
 #include "AutoInterface.h"
-#include "Log.h"
-#include "Utilities/OS.h"
+#include <microReticulum/Log.h>
+#include <microReticulum/Utilities/OS.h>
 
 #include <cstring>
 #include <algorithm>
@@ -290,17 +290,17 @@ void AutoInterface::loop() {
     }
 }
 
-void AutoInterface::send_outgoing(const Bytes& data) {
+bool AutoInterface::send_outgoing(const Bytes& data) {
     DEBUG(toString() + ".send_outgoing: data: " + data.toHex());
 
-    if (!_online) return;
+    if (!_online) return false;
 
 #ifdef ARDUINO
     // ESP32: Send to all known peers via unicast using persistent raw IPv6 socket
     // (WiFiUDP doesn't support IPv6)
     if (_data_socket < 0) {
         WARNING("AutoInterface: Data socket not ready, cannot send");
-        return;
+        return false;
     }
 
     for (const auto& peer : _peers) {
@@ -330,6 +330,7 @@ void AutoInterface::send_outgoing(const Bytes& data) {
 
     // Perform post-send housekeeping
     InterfaceImpl::handle_outgoing(data);
+    return true;
 #else
     // POSIX: Send to all known peers via unicast
     for (const auto& peer : _peers) {
@@ -354,6 +355,7 @@ void AutoInterface::send_outgoing(const Bytes& data) {
 
     // Perform post-send housekeeping
     InterfaceImpl::handle_outgoing(data);
+    return true;
 #endif
 }