chore: initial project structure and root configuration

Adds root-level config files: solution (.slnx), NuGet, global.json,
Docker Compose files for all services (API, dashboard, website, finder,
admin), environment example, and developer documentation.

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

.env.example

@@ -0,0 +1,52 @@
+# Copy to .env and adjust if ports conflict on your machine:
+#   copy .env.example .env
+
+# Host ports (what you open in the browser)
+WEB_PORT=3101          # Dashboard    http://localhost:3101/fa/login
+WEBSITE_PORT=3010      # Website      http://localhost:3010/fa
+ADMIN_WEB_PORT=3102    # Admin panel  http://localhost:3102/fa/admin/login
+API_PORT=5080          # Main API     http://localhost:5080/swagger
+ADMIN_API_PORT=5081    # Admin API    http://localhost:5081/swagger
+
+# Optional: expose DB/Redis on host (for local tools). Change if already in use.
+POSTGRES_PORT=5434
+REDIS_PORT=6381
+
+# Browser must reach the API on the host (not Docker service names)
+NEXT_PUBLIC_API_URL=http://localhost:5080
+NEXT_PUBLIC_ADMIN_API_URL=http://localhost:5081
+
+# Marketing website — public URL (used for sitemap, JSON-LD, canonical)
+NEXT_PUBLIC_SITE_URL=http://localhost:3010
+
+# API Docker base images (if build fails — see docs/DOCKER.md)
+# DOTNET_SDK_IMAGE=mcr.microsoft.com/dotnet/sdk:10.0
+# DOTNET_ASPNET_IMAGE=mcr.microsoft.com/dotnet/aspnet:10.0
+
+# --- API (docker-compose / Arvan) ---
+# ConnectionStrings__DefaultConnection=Host=postgres;Port=5432;Database=meezi;Username=meezi;Password=...
+# ConnectionStrings__Redis=redis:6379
+# Jwt__Key=<32+ char secret>
+# App__PublicBaseUrl=http://localhost:5080
+# App__QrPublicBaseUrl=http://localhost:3101
+# Billing__DashboardBaseUrl=http://localhost:3101
+# RUN_MIGRATIONS=true
+
+# ZarinPal (empty = mock payment in dev)
+# Get your merchant ID from: https://panel.zarinpal.com → API → MerchantID
+ZARINPAL_MERCHANT_ID=
+ZARINPAL_SANDBOX=true
+
+# Snappfood webhook HMAC secret (dev default in appsettings)
+# Snappfood__WebhookSecret=meezi-dev-snappfood-secret
+
+# Taraz / سامانه مودیان (optional; stub without cert)
+# Taraz__Username=
+# Taraz__Password=
+# Taraz__CertificatePath=
+
+# Kavenegar SMS (empty = OTP logged to API console in dev)
+# Kavenegar__ApiKey=
+
+# CORS (comma-separated origins for production)
+# Cors__Origins__0=https://app.meezi.ir