feat: implement FTPS deployment script

Add automated deployment script that uploads the Hugo-built site to
www.markusgraf.ch via FTPS. Implementation includes:

- scripts/deploy.sh: Deployment script with full functionality
  - Prerequisite checks (public/, lftp, FTPS_PASSWORD)
  - FTPS connection with SSL/TLS to www.markusgraf.ch
  - Mirror upload from public/ to httpsdocs/ with parallel transfers
  - Colored output with progress reporting
  - Comprehensive error handling with actionable messages

- DEPLOYMENT.md: Complete deployment documentation
  - Setup instructions and prerequisites
  - Usage examples and workflow
  - Security best practices
  - Troubleshooting guide

- .gitignore: Add entries for .env files to prevent credential leaks

- tasks.md: Mark all implementation tasks as completed

All spec requirements satisfied:
- FTPS Deployment Script provided (scripts/deploy.sh:1)
- Secure Credential Management via environment variables
- Deployment Status Feedback with colored output
- Deployment Prerequisites verified before upload

Tested with missing prerequisites, all checks working correctly.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

DEPLOYMENT.md

@@ -0,0 +1,184 @@
+# Deployment Guide
+
+This guide explains how to deploy the Hugo-built static site to the production server at www.markusgraf.ch.
+
+## Prerequisites
+
+Before deploying, ensure you have:
+
+1. **Built the site**: Run `hugo build` to generate the `public/` directory
+2. **lftp installed**: The deployment script requires the `lftp` command-line tool
+3. **FTPS credentials**: You need the FTPS password for the server
+
+### Installing lftp
+
+If `lftp` is not installed on your system:
+
+```bash
+# Ubuntu/Debian
+sudo apt-get install lftp
+
+# macOS
+brew install lftp
+
+# Fedora
+sudo dnf install lftp
+```
+
+## Deployment Process
+
+### 1. Build the Site
+
+First, build the Hugo site:
+
+```bash
+hugo build
+```
+
+This generates the static files in the `public/` directory.
+
+### 2. Set Environment Variable
+
+Set the FTPS password as an environment variable:
+
+```bash
+export FTPS_PASSWORD='your-password-here'
+```
+
+**Important**: Never commit passwords to version control. The password should only be stored as an environment variable.
+
+### 3. Run the Deployment Script
+
+Execute the deployment script:
+
+```bash
+./scripts/deploy.sh
+```
+
+The script will:
+- Check that all prerequisites are met
+- Connect to www.markusgraf.ch via FTPS
+- Upload all files from `public/` to `httpsdocs/` on the server
+- Display progress and completion status
+
+### Complete Example
+
+Here's the full workflow:
+
+```bash
+# Build the site
+hugo build
+
+# Set the password (only needed once per session)
+export FTPS_PASSWORD='your-password'
+
+# Deploy
+./scripts/deploy.sh
+```
+
+## Server Configuration
+
+The deployment script uses the following configuration:
+
+- **Server**: www.markusgraf.ch
+- **Protocol**: FTPS (FTP over SSL/TLS)
+- **Username**: gurix
+- **Target Directory**: httpsdocs/
+- **Source Directory**: public/
+
+## Security Notes
+
+### Credential Management
+
+- **Never** hardcode passwords in scripts or configuration files
+- **Never** commit passwords to version control
+- Use environment variables to pass credentials securely
+- The deployment script never displays passwords in its output
+
+### Optional: Using .env Files
+
+For convenience, you can create a `.env` file (which is ignored by git):
+
+```bash
+# .env
+FTPS_PASSWORD=your-password
+```
+
+Then source it before deployment:
+
+```bash
+source .env
+./scripts/deploy.sh
+```
+
+## Troubleshooting
+
+### Error: "Directory 'public' does not exist"
+
+**Cause**: The Hugo site hasn't been built yet.
+
+**Solution**: Run `hugo build` before deploying.
+
+### Error: "lftp is not installed"
+
+**Cause**: The `lftp` tool is not available on your system.
+
+**Solution**: Install lftp using the instructions above.
+
+### Error: "FTPS_PASSWORD environment variable is not set"
+
+**Cause**: The password environment variable hasn't been set.
+
+**Solution**: Run `export FTPS_PASSWORD='your-password'` before deploying.
+
+### Connection Failures
+
+**Cause**: Network issues or incorrect credentials.
+
+**Solutions**:
+- Verify your internet connection
+- Check that the password is correct
+- Ensure the server (www.markusgraf.ch) is accessible
+- Verify firewall settings aren't blocking FTPS (port 21)
+
+### Partial Upload Failures
+
+**Cause**: Network interruption during upload.
+
+**Solution**: Simply run the deployment script again. The `mirror` command will resume and complete the upload.
+
+## Advanced Usage
+
+### Testing Without Deploying
+
+To test the script without actually uploading files, you can modify the `deploy()` function temporarily to use the `--dry-run` flag:
+
+```bash
+mirror --reverse --delete --verbose --parallel=3 --dry-run $SOURCE_DIR $TARGET_DIR;
+```
+
+### Deployment from CI/CD
+
+For automated deployments from CI/CD pipelines:
+
+1. Store `FTPS_PASSWORD` as a secret in your CI/CD system
+2. Ensure the CI/CD environment has `lftp` installed
+3. Run the deployment script after successful builds
+
+Example GitHub Actions workflow snippet:
+
+```yaml
+- name: Deploy to server
+  env:
+    FTPS_PASSWORD: ${{ secrets.FTPS_PASSWORD }}
+  run: ./scripts/deploy.sh
+```
+
+## Support
+
+If you encounter issues not covered in this guide:
+
+1. Check the server logs
+2. Verify network connectivity to www.markusgraf.ch
+3. Ensure the `httpsdocs/` directory exists on the server
+4. Contact your hosting provider for server-side issues