chore(web): remove now view

[tyler-dane]

Intent

The /now view is not used by anyone anymore, so this PR removes it instead of keeping hidden or redirected paths around. The goal is to reduce UX surface area and delete the related code paths so future navigation and shortcut work only has to account for Day and Week.

What changed

• Removed the /now route, ROOT_ROUTES.NOW, and VIEW_SHORTCUTS.now.
• Deleted the full packages/web/src/views/Now tree, including Now-only components, hooks, providers, shortcut handlers, and tests.
• Removed the global N navigation shortcut, Now command-palette entries, Now shortcut overlay/sidebar hints, and the Now option from SelectView.
• Updated SelectView/navigation/shortcut/e2e tests to cover the remaining Day and Week behavior.
• Cleaned demo seed text and docs/acceptance runbooks that previously advertised Now mode.

Reviewer notes

There is intentionally no redirect or workaround for /now; with the route removed, it falls through to the existing app routing behavior. Review should focus on whether any user-visible entry point still suggests Now exists: view dropdown, command palette, shortcut overlays, global shortcuts, demo tasks, e2e tests, and docs.

The follow-up e2e fix removes stale Playwright assertions that expected the view dropdown to include Now and keyboard-select /now.

Validation

• bun test:web passed: 1003 tests, 0 failures
• bun type-check passed
• bun lint passed
• bunx playwright test e2e/navigation/week-view-switch.spec.ts --project=chromium-desktop passed: 5 tests, 0 failures
• bun test:e2e passed: 45 tests, 0 failures
• Reference scan found no deleted Now route/view symbols: /now, ROOT_ROUTES.NOW, VIEW_SHORTCUTS.now, views/Now, useNowShortcuts, nowShortcuts, isNow