feat: per-contact actions, device settings, a companion CLI and your contact's QR code

- Nodes: telemetry permissions per contact, reset path, share nearby
  (L1 options menu; L2 node card with "Can ask for" switches)
- Settings > Privacy: fixed position (typed in, from a waypoint, cleared)
  and the Bluetooth PIN; Settings > System: factory reset, asked twice
- Companion CLI (CMD_RUN_CLI_COMMAND 66 / RESP_CODE_CLI_REPLY 29, as
  upstream; FIRMWARE_VER_CODE 14): upstream's command names plus a key for
  every schema setting (get / set / keys)
- Screenshots move to 0x7E; tools/screenshot.py falls back to 66 / 29
- Your contact as a QR code (meshcore://contact/add): Status > System on
  ui-new, Settings > About on the L2; Nayuki's qrcodegen made header-only

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

examples/companion_radio/main.cpp

@@ -694,4 +694,17 @@ extern "C" EMSCRIPTEN_KEEPALIVE int sim_test_login_first_repeater(const char* pa
   uint32_t est_timeout;
   return the_mesh.sendRoomLogin(ci, password, est_timeout) ? 1 : 0;
 }
+
+// The companion CLI (CMD_RUN_CLI_COMMAND) without a transport: the text in,
+// the reply out, as the app's console gets it.
+extern "C" EMSCRIPTEN_KEEPALIVE const char* sim_cli(const char* command) {
+  static char reply[MAX_FRAME_SIZE];
+  reply[0] = 0;
+  if (!g_sim_ready) return reply;
+  if (!the_mesh.handleCliCommand(command, reply, sizeof(reply))) {
+    size_t at = strlen(reply);
+    snprintf(reply + at, sizeof(reply) - at, "Unknown command");
+  }
+  return reply;
+}
 #endif