docs: restructure documentation into organized folders

Organized docs into logical subdirectories:

**New Structure:**
- docs/
  - README.md (index with quick links)
  - PROJECT_PLAN.md (root level - main roadmap)
  - development/
    - getting-started.md (5-min quickstart)
    - local-setup.md (detailed Docker Compose guide)
    - workflow.md (daily development)
    - git-workflow.md (branching strategy)
  - architecture/
    - overview.md (tech stack, design)
    - database.md (schema, RLS, migrations)
    - api.md (endpoints, functions)
  - deployment/
    - production.md (Docker, Coolify)
    - ci-cd.md (automated pipelines)

**Cleaned Up:**
- Moved DEV_SETUP.md → docs/development/local-setup.md
- Removed outdated SETUP.md (referenced old Coolify setup)
- Replaced with getting-started.md (current Docker Compose flow)
- Updated README.md links to new structure

All paths tested, no broken links.

docs/development/getting-started.md

@@ -0,0 +1,189 @@
+# Getting Started with Pantry Development
+
+Welcome! This guide will get you from zero to running Pantry locally in ~5 minutes.
+
+## 🎯 What You'll Build
+
+A self-hosted kitchen inventory app with:
+- Inventory management (add, edit, delete items)
+- Tag-based organization (Fridge, Freezer, Dairy, etc.)
+- Unit conversions (g, kg, L, cups)
+- Barcode scanning (coming soon)
+- PWA features (offline, installable)
+
+## ⚡ Quick Start
+
+### Prerequisites
+
+- **Docker** & **Docker Compose** - [Install](https://docs.docker.com/get-docker/)
+- **Bun** - [Install](https://bun.sh): `curl -fsSL https://bun.sh/install | bash`
+- **Git**
+
+### One-Command Setup
+
+```bash
+# Clone the repo
+git clone https://gitea.jeanlucmakiola.de/pantry-app/pantry.git
+cd pantry
+
+# Run the setup script
+./dev.sh
+```
+
+That's it! The script will:
+1. ✅ Start Supabase services (Docker Compose)
+2. ✅ Wait for services to initialize
+3. ✅ Install frontend dependencies
+4. ✅ Launch Nuxt dev server
+
+### Access the App
+
+| Service | URL | Purpose |
+|---------|-----|---------|
+| **App** | `http://localhost:3000` | Main frontend |
+| **Supabase Studio** | `http://localhost:54323` | Database admin UI |
+| **API** | `http://localhost:54321` | Backend API |
+
+## 🎮 Try It Out
+
+1. Open `http://localhost:3000`
+2. Click **"Add Manually"** to create your first item
+3. Fill in:
+   - Name: "Milk"
+   - Quantity: 1
+   - Unit: Liter
+   - Tags: Fridge, Dairy
+   - Expiry: Set a date
+4. Click **"Add Item"** and see it in the grid!
+
+### Explore Features
+
+- **Edit item:** Click "Edit" on any card
+- **Adjust quantity:** Use +/- buttons
+- **Delete item:** Click "Delete" (confirms first)
+- **View database:** Open Supabase Studio at `:54323`
+
+## 📁 Project Structure
+
+```
+pantry/
+├── app/                      # Nuxt 4 frontend
+│   ├── components/           # Vue components
+│   │   └── inventory/        # Inventory UI (List, Card, Forms)
+│   ├── composables/          # Data hooks (useInventory, useSupabase)
+│   ├── pages/                # Routes (index, scan, settings)
+│   └── types/                # TypeScript definitions
+├── supabase/
+│   └── migrations/           # Database schema (001-005)
+├── docker-compose.yml        # Supabase services
+├── docker/
+│   └── kong.yml              # API gateway config
+└── docs/                     # Documentation
+```
+
+## 🛠️ Common Tasks
+
+### View Logs
+
+```bash
+# All services
+docker-compose logs -f
+
+# Just the database
+docker-compose logs -f db
+```
+
+### Reset Database
+
+```bash
+# Stop and remove volumes (fresh start)
+docker-compose down -v
+
+# Restart (migrations auto-apply)
+docker-compose up -d
+```
+
+### Access Database Directly
+
+```bash
+# psql CLI
+docker-compose exec db psql -U postgres -d postgres
+
+# Or use Supabase Studio (GUI)
+open http://localhost:54323
+```
+
+### Stop Everything
+
+```bash
+# Stop services (keep data)
+docker-compose stop
+
+# Stop and remove everything
+docker-compose down -v
+```
+
+## 🔍 What's Included
+
+### Database (Pre-seeded)
+
+**30 Units:**
+- Weight: g, kg, mg, lb, oz
+- Volume: mL, L, cup, tbsp, tsp
+- Count: piece, dozen, bottle, can, jar
+
+**33 Tags:**
+- Position: Fridge, Freezer, Pantry
+- Type: Dairy, Meat, Vegetables, Fruits
+- Dietary: Vegan, Gluten-Free, Organic
+- Custom: Low Stock, To Buy, Meal Prep
+
+### Features (Working Now)
+
+- ✅ Add/Edit/Delete inventory items
+- ✅ Tag selection (multi-select)
+- ✅ Unit conversions
+- ✅ Expiry date tracking with warnings
+- ✅ Responsive layout (mobile-ready)
+- ✅ Quantity quick actions (+/- buttons)
+
+### Features (Coming Soon)
+
+- ⏳ Barcode scanning (Week 3)
+- ⏳ User authentication UI
+- ⏳ Tag management
+- ⏳ PWA (offline mode)
+
+## 📚 Next Steps
+
+### Learn the Stack
+
+1. **[Architecture Overview](../architecture/overview.md)** - Tech stack and design decisions
+2. **[Database Schema](../architecture/database.md)** - Tables and relationships
+3. **[Development Workflow](workflow.md)** - Daily development process
+
+### Make Your First Change
+
+1. Pick an issue from Gitea
+2. Create a branch: `git checkout -b feature/your-feature`
+3. Make changes, test locally
+4. Commit: `git commit -m "feat: your feature"`
+5. Push and create PR
+
+### Troubleshooting
+
+See **[Local Setup Guide](local-setup.md)** for:
+- Port conflicts
+- Database connection issues
+- Frontend errors
+- Environment variables
+
+## 🤝 Need Help?
+
+- **Documentation:** Browse `/docs` folder
+- **Issues:** Create an issue on Gitea
+- **Local setup:** See [local-setup.md](local-setup.md)
+
+---
+
+**Ready to code?** Check out the [Development Workflow](workflow.md)!