chore: add claude md file (#244)

add file for claude, we can keep this up to date to improve the experience of using agents in it.

Author: joshsny

CLAUDE.md

@@ -0,0 +1,83 @@
+# Array Development Guide
+
+## Project Structure
+
+- Monorepo with pnpm workspaces and turbo
+- `apps/array` - Electron desktop app (React + Vite)
+- `packages/agent` - TypeScript agent framework wrapping Claude Agent SDK
+
+## Commands
+
+- `pnpm install` - Install all dependencies
+- `pnpm dev` - Run both agent (watch) and array app via mprocs
+- `pnpm dev:agent` - Run agent package in watch mode only
+- `pnpm dev:array` - Run array desktop app only
+- `pnpm build` - Build all packages (turbo)
+- `pnpm typecheck` - Type check all packages
+- `pnpm lint` - Lint and auto-fix with biome
+- `pnpm format` - Format with biome
+- `pnpm test` - Run tests across all packages
+
+### Array App Specific
+
+- `pnpm --filter array test` - Run vitest tests
+- `pnpm --filter array typecheck` - Type check array app
+- `pnpm --filter array package` - Package electron app
+- `pnpm --filter array make` - Make distributable
+
+### Agent Package Specific
+
+- `pnpm --filter agent build` - Build agent with tsup
+- `pnpm --filter agent dev` - Watch mode build
+- `pnpm --filter agent typecheck` - Type check agent
+
+## Code Style
+
+- Biome for linting and formatting (not ESLint/Prettier)
+- 2-space indentation, double quotes
+- No `console.*` in source - use logger instead (logger files exempt)
+- Path aliases required in renderer code - no relative imports
+  - `@features/*`, `@components/*`, `@stores/*`, `@hooks/*`, `@utils/*`, `@renderer/*`, `@shared/*`, `@api/*`
+- Main process path aliases: `@main/*`, `@api/*`, `@shared/*`
+- TypeScript strict mode enabled
+- Tailwind CSS classes should be sorted (biome `useSortedClasses` rule)
+
+## Architecture
+
+### Electron App (apps/array)
+
+- Main process: `src/main/` - Node.js, IPC handlers, services
+- Renderer process: `src/renderer/` - React app
+- Preload script: `src/main/preload.ts`
+- IPC bridge pattern between main/renderer
+- State management: Zustand stores in `src/renderer/stores/`
+- Testing: Vitest with React Testing Library
+
+### Agent Package (packages/agent)
+
+- Wraps `@anthropic-ai/claude-agent-sdk`
+- Git worktree management in `worktree-manager.ts`
+- PostHog API integration in `posthog-api.ts`
+- Task execution and session management
+
+## Key Libraries
+
+- React 18, Radix UI Themes, Tailwind CSS
+- TanStack Query for data fetching
+- xterm.js for terminal emulation
+- CodeMirror for code editing
+- Tiptap for rich text
+- Zod for schema validation
+
+## Environment Variables
+
+- Copy `.env.example` to `.env`
+- `ANTHROPIC_API_KEY` - Required for agent
+- `OPENAI_API_KEY` - Optional
+- `VITE_POSTHOG_*` - PostHog tracking config
+
+## Testing
+
+- Tests use vitest with jsdom environment
+- Test helpers in `src/test/`
+- Run specific test: `pnpm --filter array test -- path/to/test`