Initial monorepo scaffold: apps, packages, ADRs, CI and tests

[steflight]

Motivation

• Initialize a TypeScript npm workspace monorepo to deliver the KC-001 prototype (identities, organizations, invitations, private conversations, client-side envelopes and idempotent message delivery).
• Provide a minimal, testable in-memory API and lightweight clients (web + mobile) so business rules and contracts can be exercised before production persistence and auth are added.
• Establish developer ergonomics with docs, ADRs and a local compose manifest for future persistence and object storage integration.
• Add CI to enforce typechecking, tests and a web build in PRs and pushes to main.

Description

• Add monorepo manifests and base TS configuration (package.json, tsconfig.base.json, workspaces) and a .gitignore for typical artifacts.
• Implement apps/api using Fastify with a reusable InMemoryKladrichat domain service and WebSocket realtime endpoints, plus an apps/api test exercising invitation, conversation and idempotent message delivery.
• Add client shells: apps/web (Next.js static UI and styles) and apps/mobile (Expo Router skeleton and a simple list screen), and placeholder processes apps/workers and apps/recorder.
• Introduce packages @kladrichat/contracts, @kladrichat/domain, @kladrichat/crypto, @kladrichat/sdk, and @kladrichat/design-tokens, with unit tests for domain and crypto, ADRs, documentation and a Docker Compose manifest for Postgres/Redis/MinIO.
• Add GitHub Actions CI workflow (.github/workflows/ci.yml) to run npm install, npm run typecheck, npm test and npm run build -w @kladrichat/web on PRs and pushes.

Testing

• Ran workspace type checking with npm run typecheck which completed successfully.
• Ran the test suite with npm test, executing node:test suites for packages/domain, packages/crypto and apps/api, and all tests passed.
• Built the web app with npm run build -w @kladrichat/web which succeeded in producing a Next.js build.
• The CI workflow (.github/workflows/ci.yml) is configured to run the same sequence on PRs and pushes to main.

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