ui/phase-22: skip the no-op stance click in the races table

Clicking the already-active WAR/PEACE button still appended a
\`setDiplomaticStance\` whose \`relation\` matched the row's current
value. The engine would accept the duplicate harmlessly, but the
order tab inflates with rows that say nothing and every auto-sync
re-ships the redundant payload. Compare against the overlayed
stance (so a queued-but-not-applied change suppresses a re-click
that matches the *intended* state, not just the server snapshot)
and short-circuit when they agree. Mirrors the vote picker, which
already had the same guard.

vitest.config.ts: \`mergeConfig\` refuses callback-form base
configs, so resolve \`vite.config.ts\`'s callback with the test
context first and merge the plain object. Surfaced after the
\`loadEnv\` migration switched the root config to the callback
form.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

ui/frontend/vitest.config.ts

@@ -1,9 +1,15 @@
 import { defineConfig, mergeConfig } from "vitest/config";
 import viteConfig from "./vite.config";
 
-export default mergeConfig(
-	viteConfig,
-	defineConfig({
+// `vite.config.ts` exports a `defineConfig(({ mode }) => …)` callback
+// so the dev server can load `.env*` files through Vite's `loadEnv`.
+// `mergeConfig` does not accept callback-form configs, so resolve the
+// callback here with the same context Vitest would supply, then hand
+// the plain object to the merge.
+export default defineConfig(async (ctx) => {
+	const resolved =
+		typeof viteConfig === "function" ? await viteConfig(ctx) : viteConfig;
+	return mergeConfig(resolved, {
 		resolve: {
 			// Force the browser entry of Svelte so `mount` is available in jsdom.
 			conditions: ["browser"],
@@ -14,5 +20,5 @@ export default mergeConfig(
 			globals: true,
 			setupFiles: ["./tests/setup.ts"],
 		},
-	}),
-);
+	});
+});