Release v0.9.75 runtime and onboarding update

Ship the 0.9.75 source update with improved startup/runtime hardening, operator API key onboarding, Meshtastic MQTT controls, Infonet/MeshChat separation, desktop package versioning, and aircraft telemetry refinements.

Also updates focused backend/frontend tests for node settings, Meshtastic MQTT settings, and desktop runtime behavior.

frontend/package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "frontend",
-  "version": "0.9.7",
+  "version": "0.9.75",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "frontend",
-      "version": "0.9.7",
+      "version": "0.9.75",
       "dependencies": {
         "@mapbox/point-geometry": "^1.1.0",
         "@tauri-apps/plugin-process": "^2.3.1",