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/KeyboardWidget.h

@@ -61,9 +61,9 @@ struct KeyboardWidget {
     const int lh      = display.getLineHeight();
     const int cw      = display.getCharWidth();
     const int cell_w  = display.width() / KB_COLS_CHAR;
-    const int cell_h  = lh + 1;
-    const int sep_y   = lh + 1;
-    const int chars_y = sep_y + 2;
+    const int sep_y   = lh;           // tight separator: preview row height only
+    const int chars_y = sep_y + 1;
+    const int cell_h  = (display.height() - chars_y) / (KB_ROWS_CHAR + 1);
     const int spec_y  = chars_y + KB_ROWS_CHAR * cell_h;
     const int spec_w  = display.width() / KB_SPECIAL;