feat: Introduce Nucleo as the main AI agent identity

- Add Nucleo atom logo with animated orbiting electrons
- Redesign FAB with glassmorphism effect and purple gradient
- Add connection indicator (green dot) when terminal is open
- Update FloatingTerminal header with Nucleo branding
- Add PermissionRequest hook support with red alert animation
- Document Nucleo in README with visual states table
- Create official Nucleo logo SVG in docs/

docs/nucleo-logo.svg

@@ -0,0 +1,61 @@
+<svg width="120" height="120" viewBox="0 0 120 120" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <defs>
+    <radialGradient id="coreGradient" cx="50%" cy="30%" r="60%">
+      <stop offset="0%" stop-color="#c4b5fd"/>
+      <stop offset="50%" stop-color="#a78bfa"/>
+      <stop offset="100%" stop-color="#6366f1"/>
+    </radialGradient>
+    <linearGradient id="orbitGradient1" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" stop-color="#818cf8" stop-opacity="0.9"/>
+      <stop offset="50%" stop-color="#a78bfa" stop-opacity="0.5"/>
+      <stop offset="100%" stop-color="#818cf8" stop-opacity="0.9"/>
+    </linearGradient>
+    <linearGradient id="electronGradient" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" stop-color="#e0e7ff"/>
+      <stop offset="100%" stop-color="#a78bfa"/>
+    </linearGradient>
+    <filter id="glow" x="-50%" y="-50%" width="200%" height="200%">
+      <feGaussianBlur stdDeviation="3" result="blur"/>
+      <feMerge>
+        <feMergeNode in="blur"/>
+        <feMergeNode in="SourceGraphic"/>
+      </feMerge>
+    </filter>
+    <filter id="coreGlow" x="-100%" y="-100%" width="300%" height="300%">
+      <feGaussianBlur stdDeviation="6" result="blur"/>
+      <feMerge>
+        <feMergeNode in="blur"/>
+        <feMergeNode in="SourceGraphic"/>
+      </feMerge>
+    </filter>
+  </defs>
+
+  <!-- Background circle (subtle) -->
+  <circle cx="60" cy="60" r="55" fill="none" stroke="#4f46e5" stroke-width="1" opacity="0.2"/>
+
+  <!-- Orbital rings -->
+  <ellipse cx="60" cy="60" rx="45" ry="18" stroke="url(#orbitGradient1)" stroke-width="2" fill="none" transform="rotate(-30 60 60)" opacity="0.7"/>
+  <ellipse cx="60" cy="60" rx="45" ry="18" stroke="url(#orbitGradient1)" stroke-width="2" fill="none" transform="rotate(30 60 60)" opacity="0.5"/>
+  <ellipse cx="60" cy="60" rx="45" ry="18" stroke="url(#orbitGradient1)" stroke-width="2" fill="none" transform="rotate(90 60 60)" opacity="0.6"/>
+
+  <!-- Core nucleus with glow -->
+  <circle cx="60" cy="60" r="18" fill="url(#coreGradient)" filter="url(#coreGlow)"/>
+  <circle cx="60" cy="60" r="14" fill="url(#coreGradient)" opacity="0.8"/>
+  <circle cx="55" cy="55" r="5" fill="white" opacity="0.4"/>
+
+  <!-- Electrons with glow -->
+  <circle cx="60" cy="15" r="7" fill="url(#electronGradient)" filter="url(#glow)">
+    <animateTransform attributeName="transform" type="rotate" from="0 60 60" to="360 60 60" dur="4s" repeatCount="indefinite"/>
+  </circle>
+  <circle cx="100" cy="70" r="6" fill="url(#electronGradient)" filter="url(#glow)">
+    <animateTransform attributeName="transform" type="rotate" from="120 60 60" to="480 60 60" dur="5s" repeatCount="indefinite"/>
+  </circle>
+  <circle cx="20" cy="70" r="6" fill="url(#electronGradient)" filter="url(#glow)">
+    <animateTransform attributeName="transform" type="rotate" from="240 60 60" to="600 60 60" dur="4.5s" repeatCount="indefinite"/>
+  </circle>
+
+  <!-- Small accent electrons -->
+  <circle cx="60" cy="105" r="4" fill="#c4b5fd" opacity="0.6">
+    <animateTransform attributeName="transform" type="rotate" from="180 60 60" to="540 60 60" dur="6s" repeatCount="indefinite"/>
+  </circle>
+</svg>