M2 step 4: GNSS mark in the Status Bar; the clock follows the Fix

Q61: a muted G while searching (or the receiver is silent), G with a 2D
Fix, G and the satellite count with a 3D Fix; nothing when GNSS is off.
Verified on the device by a window: 3D Fix, 9 of 11 satellites used
(GPS, GLONASS, BeiDou), HDOP 1.3, Status Bar "G9", and "gnss: clock set".

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01EhqxQ49eCju4CzKYNjZzwT

src/main.cpp

@@ -91,6 +91,14 @@ static StatusInfo currentStatus() {
     s.sdLevel = storageState.level;
     s.compose = keyMapper.pendingCompose();
     s.unread = irc->totalUnread();
+    if (gnssService && gnssService->on()) {
+        const auto& g = gnssService->state();
+        bool fresh = gnssService->receiving(millis());
+        s.gnss = !fresh || g.fix == gnss::FixType::None ? StatusInfo::Gnss::Searching
+                 : g.fix == gnss::FixType::TwoD        ? StatusInfo::Gnss::TwoD
+                                                       : StatusInfo::Gnss::ThreeD;
+        s.gnssSatellites = g.satellitesUsed;
+    }
     using WifiState = WifiController::State;
     switch (wifi->state()) {
         case WifiState::Connected: {