Add item icon art for all 41 item types

Self-contained full-color SVGs in data/icons/items/, one per item id, read
by the recipe-selection dialog (REQ-UI-RECIPE-ICON) and belt/port rendering
(REQ-UI-ITEM-ICON). Bold silhouette + dark outline, authored to stay legible
at ~16px belt size: rocky ore chunks, isometric ingots, riveted plates,
copper coil/wire, pictorial module devices, and dart hull silhouettes tinted
per fleet color. No config changes needed — each recipe's icon resolves to
its first output.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01Y7N59FsLA5e2kuVdqe4Uhc

bin/app/data/icons/items/drive_unit.svg

@@ -0,0 +1,6 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100" width="100" height="100">
+  <path d="M40 22 L60 22 L58 42 L72 74 L28 74 L42 42 Z" fill="#4a6ad0" stroke="#101a38" stroke-width="3.5" stroke-linejoin="round"/>
+  <ellipse cx="50" cy="74" rx="22" ry="6" fill="#2a3a80" stroke="#101a38" stroke-width="2.5"/>
+  <path d="M40 22 L60 22" stroke="#8aa0e8" stroke-width="4" stroke-linecap="round"/>
+  <path d="M44 80 Q50 94 56 80" fill="#ffb347"/>
+</svg>