feat: add dark theme support and update homepage content

- Integrated next-themes for dark mode theming with default dark theme
- Added new UI components (GridBlink, Spotlight) and enhanced world map with cyan glow effects
- Updated homepage messaging to emphasize Mycelium as a living network with new audience imagery

src/components/ui/GridBlink.tsx

@@ -0,0 +1,64 @@
+"use client";
+
+import { useEffect, useRef } from "react";
+
+export function GridBlink() {
+  const svgRef = useRef<SVGSVGElement>(null);
+  const maxActive = 3; // ✅ limit active squares
+
+  useEffect(() => {
+    const svg = svgRef.current;
+    if (!svg) return;
+
+    const squares = Array.from(svg.querySelectorAll<SVGRectElement>(".blink-square"));
+
+    function scheduleBlink() {
+      // ✅ only blink if we have too few active
+      const currentlyActive = squares.filter(sq => sq.classList.contains("active"));
+      if (currentlyActive.length < maxActive) {
+        const sq = squares[Math.floor(Math.random() * squares.length)];
+        sq.classList.add("active");
+
+        const duration = 800 + Math.random() * 1000; // ✅ slower fade-out
+        setTimeout(() => {
+          sq.classList.remove("active");
+        }, duration);
+      }
+
+      // ✅ slower scheduling
+      setTimeout(scheduleBlink, 300 + Math.random() * 600);
+    }
+
+    scheduleBlink();
+  }, []);
+
+  const rows = 20;
+  const cols = 32;
+  const size = 40;
+
+  return (
+    <svg
+      ref={svgRef}
+      className="pointer-events-none absolute inset-0 z-0"
+      style={{ width: "100%", height: "100%" }}
+    >
+      {Array.from({ length: rows * cols }).map((_, i) => {
+        const x = (i % cols) * size;
+        const y = Math.floor(i / cols) * size;
+        return (
+          <rect
+            key={i}
+            className="blink-square"
+            x={x}
+            y={y}
+            width={size}
+            height={size}
+            fill="transparent"
+            stroke="#efefef"
+            strokeWidth="1"
+          />
+        );
+      })}
+    </svg>
+  );
+}