feat: Initialize NxMesh project with Docker, Nginx, PostgreSQL, and Rust backend

- Add Docker Compose configuration for development environment
- Create Nginx configuration files for routing and health checks
- Set up PostgreSQL database with health checks
- Add .dockerignore and .gitignore files to exclude unnecessary files
- Initialize Cargo.toml and Cargo.lock for Rust dependencies
- Include GNU General Public License for project
- Add README.md for project description
- Create Justfile for development workflow commands

.devcontainer/Dockerfile

@@ -0,0 +1,20 @@
+FROM mcr.microsoft.com/devcontainers/base:ubuntu-22.04
+
+# Avoid prompts from apt
+ENV DEBIAN_FRONTEND=noninteractive
+
+# Install system dependencies that don't have devcontainer features
+RUN apt-get update && apt-get install -y \
+    pkg-config \
+    libssl-dev \
+    postgresql-client \
+    protobuf-compiler \
+    && rm -rf /var/lib/apt/lists/*
+
+# Set working directory
+WORKDIR /workspace
+
+# Note: Rust, Bun, and just are installed via devcontainer features
+# cargo-binstall, cargo-watch, cargo-edit, and sea-orm-cli are installed via postCreateCommand
+
+CMD [ "sleep", "infinity" ]