Add comprehensive E2E test suite and Docker test infrastructure
System specs (10 new files, 880 lines):
- Fork branding: brand name display, personalization form, upstream attribution
- Account logo: section visibility, placeholder, attached logo display
- Signing flow: enforced order, signature clear/redraw, resubmit, optional fields, decline
- Role-based access: admin/editor/viewer nav and button visibility matrix
- SMS/SSO settings: placeholder visibility in single-tenant mode
- Submission lifecycle: send-to-recipients, sign flow, completion verification
- Template CRUD: restore archived, share link toggle, folder navigation
- Feature toggles: 7 toggle integration tests (decline, delegate, reason, order, typed sig, MFA, resubmit)
API request specs (1 new file, 91 lines):
- User show, template clone, submission documents, form/submission events, tools merge
Docker test infrastructure:
- Dockerfile.test: Ruby 4.0.5 + Chrome + Node 20 + pdfium + libvips
- docker-compose.test.yml: PostgreSQL 14 + test service with volume caching
- bin/test: convenience script for running tests locally
Fix existing specs to match actual HTML/CSS:
- Rename .navbar selectors (no such class exists)
- Fix button/link selectors for Clone/Archive/Restore
- Fix modal selectors for share link and send-to-recipients
- Fix signing reason select selector (Vue-rendered)
- Fix complete button selector (Vue teleport)
- Fix awaiting view text (uppercase CSS)
- Fix pending/completed status text (uppercase badges)