feat: add Docker support for cross-platform easy setup

Implements comprehensive Docker support to eliminate Python version and dependency concerns.
Users can now run the MCP server in a container with automatic path translation between
host and container filesystems.

Key features:
- Dockerfile with multi-architecture support (amd64/arm64)
- Automatic path translation using WORKSPACE_ROOT environment variable
- Setup scripts for all platforms (Bash, CMD, PowerShell)
- GitHub Actions workflow for automated Docker Hub publishing
- Secure non-root container execution
- Read-only volume mounts by default

The setup process is now simplified to:
1. Run setup-docker-env script to generate .env and Claude config
2. Build the Docker image
3. Copy generated config to Claude Desktop

No Python installation or virtual environment management required.

Fixes #3

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

setup-docker-env.ps1

@@ -0,0 +1,64 @@
+# PowerShell script to set up .env file for Docker usage on Windows
+
+Write-Host "Setting up .env file for Gemini MCP Server Docker..."
+
+# Get the current working directory (absolute path)
+$CurrentDir = Get-Location
+
+# Check if .env already exists
+if (Test-Path .env) {
+    Write-Host "Warning: .env file already exists! Skipping creation." -ForegroundColor Yellow
+    Write-Host ""
+} else {
+    # Create the .env file
+    @"
+# Gemini MCP Server Docker Environment Configuration
+# Generated on $(Get-Date)
+
+# The absolute path to your project root on the host machine
+# This should be the directory containing your code that you want to analyze
+WORKSPACE_ROOT=$CurrentDir
+
+# Your Gemini API key (get one from https://makersuite.google.com/app/apikey)
+# IMPORTANT: Replace this with your actual API key
+GEMINI_API_KEY=your-gemini-api-key-here
+
+# Optional: Set logging level (DEBUG, INFO, WARNING, ERROR)
+# LOG_LEVEL=INFO
+"@ | Out-File -FilePath .env -Encoding utf8
+
+    Write-Host "Created .env file" -ForegroundColor Green
+    Write-Host ""
+}
+
+Write-Host "Next steps:"
+Write-Host "1. Edit .env and replace 'your-gemini-api-key-here' with your actual Gemini API key"
+Write-Host "2. Run 'docker build -t gemini-mcp-server .' to build the Docker image"
+Write-Host "3. Copy this configuration to your Claude Desktop config:"
+Write-Host ""
+Write-Host "===== COPY BELOW THIS LINE =====" -ForegroundColor Cyan
+Write-Host @"
+{
+  "mcpServers": {
+    "gemini": {
+      "command": "docker",
+      "args": [
+        "run",
+        "--rm",
+        "-i",
+        "--env-file", "$CurrentDir\.env",
+        "-v", "${CurrentDir}:/workspace:ro",
+        "gemini-mcp-server:latest"
+      ]
+    }
+  }
+}
+"@
+Write-Host "===== COPY ABOVE THIS LINE =====" -ForegroundColor Cyan
+Write-Host ""
+Write-Host "Config file location:"
+Write-Host "  Windows: %APPDATA%\Claude\claude_desktop_config.json"
+Write-Host ""
+Write-Host "Note: The configuration above mounts the current directory ($CurrentDir)"
+Write-Host "as the workspace. You can change this path to any project directory you want to analyze."
+Write-Host "Docker on Windows accepts both forward slashes and backslashes in paths."