style(visual-fidelity): pages-public — batches A,D,F,G,H

- about.vue: promote h3 → h2 on circle headings (h1→h2→h2→h2)
- coming-soon.vue: font-weight 700 → 600
- members/[id].vue: inline circle badge → <CircleBadge/>; hero size 42→36
- community-guidelines.vue: padding + font-size off-scale snaps
- board.vue: loading/empty padding 60→64
- series/index.vue, join.vue: padding off-scale snaps

app/pages/board.vue

@@ -357,13 +357,13 @@ onMounted(async () => {
 
 /* ---- LOADING / EMPTY ---- */
 .loading-state {
-  padding: 60px 24px;
+  padding: 64px 24px;
   text-align: center;
   color: var(--text-faint);
   font-size: 12px;
 }
 .empty-state {
-  padding: 60px 24px;
+  padding: 64px 24px;
   text-align: center;
 }
 .empty-title {