test(smoke): fix three stale assertions surfaced by triage

- 01 calculator: page lives at /calculator/ (confirmed live), not
  /reconstitution-calculator/ — the 404 failed all 3 calc tests.
- 00 homepage: brand title is 'Peptide Repo' (with space); regex /peptiderepo/i
  never matched. Broadened to /peptide ?repo/i.
- 03 admin: required-plugin slug is 'prautoblogger' (WP dir), not 'pr-autoblogger'.

These were test bugs, not site regressions — the site serves all three correctly.

Agent-Session: cto smoke-triage

tests/00-homepage.spec.ts

@@ -29,7 +29,7 @@ test.describe('Homepage', () => {
 
   test('renders site name in page title', async ({ page }) => {
     await page.goto('/');
-    await expect(page).toHaveTitle(/peptiderepo/i);
+    await expect(page).toHaveTitle(/peptide ?repo/i);
   });
 
   test('wp-admin bar present (logged-in session)', async ({ page }) => {