perf(ci): add .dockerignore to reduce build context size

[Peleke]

Problem

Docker build sends entire project directory as context, including unnecessary files (node_modules, .git, .next, test artifacts).

Solution

Create .dockerignore to exclude:

• node_modules
• .next
• .git
• .github
• *.md
• .env*
• playwright-report
• test-results
• coverage

Expected Impact

30-50% faster context upload to Docker daemon

[Peleke]

✅ Merged in PR #5. Build time: 2m29s (5s improvement + cleaner context)