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/edit.svg

@@ -0,0 +1,14 @@
+<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="M17 3a2.85 2.85 0 1 1 4 4L7.5 20.5 2 22l1.5-5.5Z" />
+  <path d="m15 5 4 4" />
+</svg>