test: setup Playwright E2E infrastructure and smoke tests

[google-labs-jules]

Context

This PR introduces the initial setup for End-to-End (E2E) testing using Playwright, fulfilling the "Proactive Improvement" goal of the hardening pass. It establishes the infrastructure to verify main user journeys as requested in TASKS.md.

Changes

• Installed @playwright/test.
• Configured playwright.config.ts to run against a local dev server.
• Added a basic e2e/smoke.test.ts to verify the application loads and displays the correct title.
• Updated package.json with a test:e2e script.
• Patched server/migrate.ts to allow skipping the database connection check via SKIP_DB_CHECK=true environment variable. This allows the server to start for smoke testing in environments where a full database is not available (like the current verification sandbox or basic CI steps).
• Updated vitest.config.ts to exclude e2e tests from the unit test runner.
• Updated .gitignore to exclude Playwright report artifacts.
• Updated TASKS.md to reflect progress.

Verification

• npm run test:e2e: Passed (Verified smoke tests).
• npm run test: Passed (Verified no regression in unit tests).
• npm run build: Passed (Verified build stability).

Risk Analysis

• Low Risk: This change primarily adds testing infrastructure.
• The modification to server/migrate.ts is guarded by an explicit environment variable (SKIP_DB_CHECK), ensuring it does not affect production or standard development workflows unless opted-in.
• Rollback: Revert this PR.

Manager's Note

All CI checks green. Do not merge automatically.

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PR created automatically by Jules for task 14345369779571088007 started by @Doezer

[google-labs-jules]

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