Stop Sentry on logout; fix E2E + Dockerfile for merged consolidation

- sentry.client.ts: add stopSentryClient() that awaits Sentry.close() so
  the SDK tears down when a user logs out. Hub methods become no-ops
  until initSentryClient() is called again on next login.
- root.tsx: call stopSentryClient() from the user-effect when user === null.
- Add sentry-config to journal + planner Dockerfiles (was missing after
  #237 introduced the new workspace package, breaking the Dockerfile
  package check).
- Footer: replace inner <nav> with <div> — nested nav landmarks broke
  the journal "nav bar shows on all pages" e2e test (two navigation
  roles on the page).
- e2e auth: tick the required ToS checkbox in the shared registerUser
  helper so passkey registration tests pass.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

e2e/auth.test.ts

@@ -30,6 +30,8 @@ async function registerUser(page: Page, email: string, username: string) {
   // Verify both fields retained values before submitting
   await expect(page.getByLabel("Email")).toHaveValue(email);
   await expect(page.getByLabel("Username")).toHaveValue(username);
+  // Accept the Terms of Service (required)
+  await page.getByRole("checkbox").check();
   await page.getByRole("button", { name: /Register with Passkey/ }).click();
 }