Support: add a feedback email, rebrand from Donate, tighten privacy copy

src/app/App.tsx

@@ -82,8 +82,9 @@ export function App() {
             actions are a right-aligned row of icon-only buttons). The utilities
             are IconButtons — tooltips carry the full action, accessible names
             scope it ("Export workspace" vs the preview pane's per-chart
-            "Export") — then a divider sets off Donate — the one solicitation,
-            given a soft-accent wash — and the theme toggle. */}
+            "Export") — then a divider sets off Support (feedback + the one
+            donation solicitation), given a soft-accent wash — and the theme
+            toggle. */}
         <IconButton
           label="Datasets"
           onClick={() => openModal('datasets')}
@@ -117,9 +118,9 @@ export function App() {
         <Button
           variant="soft-accent"
           onClick={() => openModal('donate')}
-          title="Support Ukraine's defense"
+          title="Send feedback or support Ukraine's defense"
         >
-          Donate
+          Support
         </Button>
         <ThemeToggle />
         {/* Hidden picker for Import; restricted to JSON (spec §08). */}