chore(wails): scaffold v3 project boilerplate

Wails v3 replaces the NPM-only dev entry point. This adds the Go module,
Taskfile, build metadata, and a minimal window shell without touching
frontend logic.

Co-authored-by: Cursor <cursoragent@cursor.com>

build/appicon.icon/Assets/wails_icon_vector.svg

@@ -0,0 +1,9 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<!DOCTYPE svg PUBLIC "-//W3C//DTD SVG 1.1//EN" "http://www.w3.org/Graphics/SVG/1.1/DTD/svg11.dtd">
+<svg width="100%" height="100%" viewBox="0 0 583 533" version="1.1" xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" xml:space="preserve" xmlns:serif="http://www.serif.com/" style="fill-rule:evenodd;clip-rule:evenodd;stroke-linejoin:round;stroke-miterlimit:2;">
+    <g transform="matrix(1,0,0,1,-246,-251)">
+        <g id="Ebene1">
+            <path d="M246,251L265,784L401,784L506,450L507,450L505,784L641,784L829,251L682,251L596,567L595,567L596,251L478,251L378,568L391,251L246,251Z"/>
+        </g>
+    </g>
+</svg>