feat: scaffold monorepo with Go backend + Next.js 15 frontend

- Root monorepo: /backend (Go) + /frontend (Next.js 15)
- Go module: mgit.msbls.de/m/KanzlAI with minimal HTTP server
- Next.js 15: TypeScript strict, Tailwind CSS v4, App Router, Bun
- Root Makefile: dev, build, lint, test targets
- Root .gitignore covering Go, Node, IDE, OS files
- CLAUDE.md updated with project structure and tech stack
- .claude/CLAUDE.md with coding conventions (Go stdlib style, TS strict)

CLAUDE.md

@@ -1,19 +1,39 @@
 # KanzlAI
 
-AI-powered law firm tools.
+AI-powered toolkit for patent litigation — UPC case law search, analysis, and AI-assisted legal research.
 
 **Memory group_id:** `kanzlai`
 
-## Purpose
+## Project Structure
 
-TBD — to be defined by inventor.
+```
+backend/           Go API server
+  cmd/server/      Entry point
+  internal/        Private packages
+frontend/          Next.js 15 (TypeScript, Tailwind CSS, App Router)
+  src/app/         App Router pages
+```
 
 ## Tech Stack
 
-- Web: static site (to be decided)
-- Hosting: TBD
+- **Frontend:** Next.js 15 with TypeScript, Tailwind CSS v4, App Router, Bun
+- **Backend:** Go (standard library HTTP server)
+- **Database:** Supabase (PostgreSQL) — shared instance with other m projects
+- **AI:** Claude API
+- **Deploy:** mRiver with Caddy reverse proxy
+
+## Development
+
+```bash
+make dev-backend    # Go server on :8080
+make dev-frontend   # Next.js dev server
+make build          # Build both
+make lint           # Lint both
+make test           # Test both
+```
 
 ## Git Strategy
 
 - **main** = production
 - Feature branches: `feat/*`, `fix/*`
+- Worker branches: `mai/<worker>/<task>`