Refine branding and default to dark theme

tests/flow.spec.js

@@ -66,8 +66,9 @@ test('create → mine → mempool → inscription → block/transaction → relo
   await page.screenshot({path:`test-results/${test.info().project.name}-complete.png`,fullPage:true});
 });
 
-test('theme toggle persists explicit light/dark preference', async ({page}) => {
-  await page.emulateMedia({colorScheme:'dark'});
+for (const colorScheme of ['light', 'dark']) {
+test(`dark default and explicit theme persistence with ${colorScheme} system preference`, async ({page}) => {
+  await page.emulateMedia({colorScheme});
   await page.goto('/');
   await expect(page.locator('html')).toHaveAttribute('data-theme','dark');
   await expect(page.getByRole('button',{name:'Switch to light mode'})).toBeVisible();
@@ -76,7 +77,13 @@ test('theme toggle persists explicit light/dark preference', async ({page}) => {
   await page.reload();
   await expect(page.locator('html')).toHaveAttribute('data-theme','light');
   await expect(page.getByRole('button',{name:'Switch to dark mode'})).toBeVisible();
+  expect(await page.evaluate(() => localStorage.getItem('super-testnet-theme'))).toBe('light');
+  await page.getByRole('button',{name:'Switch to dark mode'}).click();
+  await page.reload();
+  await expect(page.locator('html')).toHaveAttribute('data-theme','dark');
+  expect(await page.evaluate(() => localStorage.getItem('super-testnet-theme'))).toBe('dark');
 });
+}
 
 test('wallet backup reload and rejected oversized or invalid input',async({page})=>{
   await page.goto('/'); await page.getByRole('button',{name:'Create test wallet'}).click();