feat(themes): summer pair JSON SoT + status CSS + recapture previews

Align summer-day/night waybar tokens with JSON roles (hierarchy split
on night; day overlay≠muted), unify bar font 13px + battery 25/10, add
VPN pill and status states (.on/.available/.recording/…). Recapture
executive-slate and neon-glass picker previews from theme-shot.

Verified: V0 contrast+wholeswap; V2 theme-shot four slugs.

themes/summer-night.json

@@ -8,10 +8,10 @@
     "base": "#2d353b",
     "mantle": "#262d32",
     "surface": "#3c474d",
-    "overlay": "#868d80",
+    "overlay": "#859289",
     "text": "#d3c6aa",
-    "subtext": "#868d80",
-    "muted": "#868d80",
+    "subtext": "#9da9a0",
+    "muted": "#7a8478",
     "accent": "#83b6af",
     "accentAlt": "#d39bb6",
     "good": "#a7c080",