brand: a workspace, tiled, with its focus lit

The ~/ with a cursor was a word drawn as a picture. The mark is now what
the app is: a workspace tiled the way the desktop tiles one, the first
window and the rest dwindling beside it with gaps between. The focused
window wears the theme's light at 135°, as the active border does, with a
soft glow, and carries the header every pane opens with, a square marker
and a rule; the others are outlines on the hull. It holds at 16 px as a lit
bar beside dim ones.

The touch icon, the 512 px copy and the banner are rendered from the same
SVG, and the screenshots are taken again with it in the bar.

web/public/favicon.svg

@@ -1,12 +1,24 @@
 <svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512">
-  <!-- ~/ and the cursor the boot screen waits with, in the theme's one light
-       on its hull, inside the corner brackets the desktop frames things in. -->
-  <rect width="512" height="512" rx="112" fill="#0c0d0b"/>
-  <rect x="12" y="12" width="488" height="488" rx="100" fill="none" stroke="#2a2f28" stroke-width="6"/>
-  <path d="M60 116 V60 H116 M396 60 H452 V116 M452 396 V452 H396 M116 452 H60 V396" fill="none" stroke="#383e35" stroke-width="6"/>
-  <g fill="none" stroke="#eef1ea" stroke-width="30" stroke-linecap="square" stroke-linejoin="round">
-    <path d="M100 276 C100 244 118 230 138 230 C168 230 172 274 202 274 C222 274 240 260 240 228"/>
-    <path d="M318 160 L262 352"/>
-  </g>
-  <rect x="340" y="320" width="76" height="32" fill="#eef1ea"/>
+  <!-- A workspace as the desktop tiles one: the first window and the rest
+       dwindling beside it, gaps between. The focused one wears the light the
+       theme gives focus, at 135° as the active border does, and the header
+       every pane opens with: a square marker and a rule. -->
+  <defs>
+    <linearGradient id="lit" x1="0" y1="0" x2="1" y2="1">
+      <stop offset="0" stop-color="#eef1ea"/><stop offset="1" stop-color="#8e978d"/>
+    </linearGradient>
+    <linearGradient id="hull" x1="0" y1="0" x2="0" y2="1">
+      <stop offset="0" stop-color="#131512"/><stop offset="1" stop-color="#090a08"/>
+    </linearGradient>
+    <filter id="glow" x="-40%" y="-40%" width="180%" height="180%"><feGaussianBlur stdDeviation="18"/></filter>
+  </defs>
+  <rect width="512" height="512" rx="112" fill="url(#hull)"/>
+  <rect x="6" y="6" width="500" height="500" rx="106" fill="none" stroke="#20241f" stroke-width="4"/>
+  <rect x="72" y="72" width="174" height="368" rx="22" fill="#eef1ea" opacity="0.22" filter="url(#glow)"/>
+  <rect x="72" y="72" width="174" height="368" rx="22" fill="url(#lit)"/>
+  <rect x="96" y="98" width="18" height="18" fill="#0c0d0b"/>
+  <rect x="128" y="105" width="94" height="4" fill="#0c0d0b" opacity="0.55"/>
+  <rect x="269" y="75" width="168" height="168" rx="19" fill="none" stroke="#4a5148" stroke-width="6"/>
+  <rect x="269" y="269" width="71" height="168" rx="19" fill="none" stroke="#4a5148" stroke-width="6"/>
+  <rect x="366" y="269" width="71" height="168" rx="19" fill="none" stroke="#4a5148" stroke-width="6"/>
 </svg>