Fix web UI scrolling issue by removing height constraints

- Remove html{height:100%} and body{min-height:100vh} that caused unwanted scrolling
- Allow content to determine natural height without forced viewport constraints
- Maintain centered layout while eliminating ghost padding below GUI

Author: jqntn

Comanche055-C89/dsky_web.c

@@ -86,9 +86,9 @@ static const char web_index_html[] =
 "<meta name='viewport' content='width=device-width,initial-scale=1'>\n"
 "<title>Comanche055 DSKY</title>\n"
 "<style>\n"
-"html,body{height:100%;}\n"
-"body{margin:0;padding:12px;background:#0b0b0b;color:#d4f7d4;font-family:Consolas,'Courier New',monospace;font-size:16px;line-height:1.45;display:flex;align-items:flex-start;justify-content:center;}\n"
-".app{width:100%;max-width:760px;box-sizing:border-box;}\n"
+"html{height:auto;}\n"
+"body{margin:0;padding:12px;background:#0b0b0b;color:#d4f7d4;font-family:Consolas,'Courier New',monospace;font-size:16px;line-height:1.45;box-sizing:border-box;}\n"
+".app{width:100%;max-width:760px;margin:0 auto;box-sizing:border-box;}\n"
 "h1{margin:0 0 12px;text-align:center;font-size:30px;line-height:1.2;}\n"
 "#status{margin:0 0 12px;text-align:center;color:#9ad09a;font-size:18px;}\n"
 "pre{margin:0;background:#111;border:1px solid #2f2f2f;padding:16px;overflow:auto;font-size:22px;line-height:1.35;}\n"