chore(icons): add edit and refresh SVGs, consolidate excel icon path

- Add edit.svg and refresh.svg icon assets
- Update excel.svg in canonical icons/ directory
- Remove duplicate icon from legacy icon/ directory

src/pygui/ISC/Tabs/icons/refresh.svg

@@ -0,0 +1,16 @@
+<svg
+  xmlns="http://www.w3.org/2000/svg"
+  width="24"
+  height="24"
+  viewBox="0 0 24 24"
+  fill="none"
+  stroke="currentColor"
+  stroke-width="2"
+  stroke-linecap="round"
+  stroke-linejoin="round"
+>
+  <path d="M3 12a9 9 0 0 1 9-9 9.75 9.75 0 0 1 6.74 2.74L21 8" />
+  <path d="M21 3v5h-5" />
+  <path d="M21 12a9 9 0 0 1-9 9 9.75 9.75 0 0 1-6.74-2.74L3 16" />
+  <path d="M3 21v-5h5" />
+</svg>