Enable 5 previously skipped e2e tests

- Fix OIDC tests with route interception for auth-methods API
- Add data-testid to DecisionCard for reliable test selection
- Fix /api/today to fetch fresh user data instead of stale cookie data
- Fix period logging test timing with proper API wait patterns
- Fix decision engine test with waitForResponse instead of timeout
- Simplify mobile viewport test locator

All 206 e2e tests now pass with 0 skipped.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

e2e/mobile.spec.ts

@@ -77,9 +77,7 @@ test.describe("mobile viewport", () => {
       await expect(settingsLink).toBeVisible();
 
       // Decision card should be visible
-      const decisionCard = page
-        .locator('[data-testid="decision-card"]')
-        .or(page.getByText(/rest|gentle|light|reduced|train/i).first());
+      const decisionCard = page.locator('[data-testid="decision-card"]');
       await expect(decisionCard).toBeVisible();
 
       // Data panel should be visible