fix: landscape e-ink layout corrections — clock overlap, keyboard overflow, bar sizing, nearby detail

- GxEPDDisplay: fontAscender only applies to sz=1 with Lemon; sz=2 (NULL font)
  was incorrectly getting a 16px cursor offset, causing clock text to render
  16px lower than expected and overlap the date line
- KeyboardWidget: compute cell_h from available screen height instead of lh+1;
  tighten sep_y to lh so the grid fits within 122px even with Lemon font (lh=20)
- SettingsScreen renderBar: constrain box size to available width so the 5th
  buzzer-volume square doesn't overflow past the right edge with Lemon font
- NearbyScreen discover detail: manually truncate b64 public key by charWidth
  to guarantee one-line rendering; use dynamic step = (height-hdr)/5 so
  Status line doesn't fall off the bottom of the screen
- NearbyScreen contacts detail: merge dist+az into one line and use dynamic
  step to fit 5 lines within the display; removes the off-screen Seen: row
- AutoAdvertScreen: replace lineStep() gap before hints with 4px fixed gap
  so both hint lines fit within the display with large fonts

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

examples/companion_radio/ui-new/AutoAdvertScreen.h

@@ -28,7 +28,7 @@ public:
     int label_y = display.listStart();
     int bar_y   = label_y + display.lineStep();
     int bar_h   = display.lineStep();
-    int tip_y   = bar_y + bar_h + display.lineStep();
+    int tip_y   = bar_y + bar_h + 4;
 
     display.drawTextCentered(display.width() / 2, 0, "AUTO-ADVERT");
     display.fillRect(0, display.headerH() - 1, display.width(), 1);