fix(setup): stop presenting ChatGPT OAuth as the default voice fallback

Doctor and dev-fresh told every user without an OpenAI key that voice could
use ChatGPT OAuth, whether or not Codex was installed. Say voice is off
until a key is added or a Codex sign-in is selected, and mark that path
experimental.

scripts/dev-fresh.sh

@@ -347,7 +347,7 @@ case "${OPENSKY_AUTH_MODE}" in
     echo "OpenSky auth: disabled (anonymous mode)"
     ;;
 esac
-[[ -n "${OPENAI_API_KEY}" ]] && echo "OpenAI key (voice + HUD summary): configured" || echo "OpenAI key: not set — GEV MIC can use ChatGPT OAuth from Provider Settings"
+[[ -n "${OPENAI_API_KEY}" ]] && echo "OpenAI key (voice + HUD summary): configured" || echo "OpenAI key (voice + HUD summary): not set — GEV MIC off unless a Codex ChatGPT sign-in is selected in Provider Settings (experimental)"
 [[ -n "${AISSTREAM_API_KEY}" ]] && echo "AISStream key (live vessels): configured" || echo "AISStream key (live vessels): not set — ships layer empty"
 if [[ -n "${GOOGLE_MAPS_API_KEY}" ]]; then
   echo "Startup map: Google Photorealistic 3D Tiles (direct)"

scripts/setup-doctor.mjs

@@ -178,7 +178,7 @@ export function buildCapabilitySummary(
     flights,
     voice: configured('OPENAI_API_KEY')
       ? 'available'
-      : 'ChatGPT/Codex OAuth can be selected at runtime',
+      : 'off until an OpenAI key is added, or a Codex ChatGPT sign-in is selected in Provider Settings (experimental)',
     vessels: configured('AISSTREAM_API_KEY') ? 'live AISStream feed' : 'off until an AISStream key is added',
     fires: configured('FIRMS_MAP_KEY') ? 'live NASA FIRMS feed' : 'off until a FIRMS key is added',
     traffic: configured('TOMTOM_API_KEY') ? 'live TomTom flow' : 'built-in traffic simulation',

src/setupDoctor.test.mjs

@@ -279,7 +279,7 @@ test('doctor describes the credential ladder without exposing values', () => {
       ...credentials,
       OPENAI_API_KEY: { configured: false },
     }).voice,
-    'ChatGPT/Codex OAuth can be selected at runtime',
+    'off until an OpenAI key is added, or a Codex ChatGPT sign-in is selected in Provider Settings (experimental)',
   );
   assert.match(capabilities.missions, /token allowance/);
   assert.equal(