test(web): add UI tests for chat, contacts, companies, deals, and settings

[Baba-2001]

Summary

Adds Vitest-based UI tests for the web app: contacts, chat, companies, deals, and settings. Includes Vitest setup and lint fixes across the test files.

What's included

Setup

• Vitest config and test setup (vitest.config.ts, __tests__/setup.ts)
• Jest-DOM matchers for assertions

Contacts (contacts.test.tsx)

• ContactForm: Fields, create vs edit, validation, submit & redirect, cancel, errors, loading state
• ContactsList: Heading, search, New Contact, empty state, table, row click → detail, loading, pagination
• ContactDetail: Loading, not found, content, Edit, Hide (confirm/cancel)
• EmptyContactsList: Message and New Contact link

Chat (chat.test.tsx)

• ChatInput: Render, send, mentions
• NewChatPage: Flow and behaviour

Companies (companies.test.tsx — 29 tests)

• CompanyForm: All fields, create vs edit, validation (required name, website URL), submit & redirect, cancel, errors, loading
• CompaniesList: Heading, search, New Company, empty state, table, row click → detail, loading, pagination
• CompanyDetail: Loading, not found, content, Edit, Hide (confirm/cancel)
• EmptyCompaniesList: Message and New Company link

Deals (deals.test.tsx — 28 tests)

• DealForm: Key fields, create vs edit, validation (title, value), submit & redirect, cancel, errors, loading
• DealsList: Heading, search, New Deal, empty state, table, row click → detail, loading, pagination
• DealDetail: Loading, not found, content, Edit, Hide (confirm/cancel)
• EmptyDealsList: Message and New Deal link

Settings (settings.test.tsx — 15 tests)

• SettingsPage: Heading, Integrations & Connections, GitHub App, GitHub, Google Calendar, Connected/Not connected
• ConnectGitHub: Loading skeleton, Connected state, Connect button, linkSocial, Connecting… state
• InstallGitHubApp: Loading skeleton, Installed vs not installed, Install/Re-install, redirect on Install