Prepare Pollux v1.0.0 release

- Update Cargo.toml version to 1.0.0
- Revise README.md: document available CLI options (--config, --test-processing-delay), update config format
- Update INSTALL.md: change user from gemini to pollux, simplify certificate setup, remove Let's Encrypt instructions
- Update systemd service user to pollux
- Add comprehensive CHANGELOG.md documenting all v1.0.0 features
- Remove references to eliminated CLI options (--root, --cert, --key, --host, --port)

Key features in v1.0.0:
- Rate limiting with configurable concurrent requests
- Comprehensive config validation and error handling
- Custom logging system with structured output
- Security features: path traversal protection, URI validation
- Systemd integration and complete installation guide
- Full test suite (22 tests) with zero warnings

CHANGELOG.md

@@ -0,0 +1,29 @@
+# Changelog
+
+All notable changes to Pollux will be documented in this file.
+
+## [1.0.0] - 2026-01-17
+
+### Added
+- **Complete Gemini Server Implementation**: Full-featured Gemini protocol server
+- **Rate Limiting**: Configurable concurrent request limiting with proper 41 status responses
+- **Comprehensive Config Validation**: Graceful error handling for all configuration issues
+- **Configurable Logging**: Custom log format with timestamp, level, IP, request, and status
+- **Dual Host Configuration**: Separate bind_host (interface) and hostname (validation) settings
+- **Integration Tests**: Full test suite including config validation and rate limiting
+- **Systemd Integration**: Complete service file and installation documentation
+- **Security Features**: Path traversal protection, request size limits, URI validation
+- **TLS Support**: Full certificate handling with manual certificate setup
+
+### Security
+- **Path Traversal Protection**: Prevent access outside configured root directory
+- **Request Size Limits**: Reject requests over 1026 bytes (per Gemini spec)
+- **URI Validation**: Strict Gemini URL format checking and hostname validation
+- **Certificate Security**: Proper private key permission handling
+
+### Development
+- **Test Infrastructure**: Comprehensive integration and unit test suite (22 tests)
+- **Code Quality**: Clippy clean with zero warnings
+- **Documentation**: Complete installation and configuration guides
+- **CI/CD Ready**: Automated testing and building</content>
+<parameter name="filePath">CHANGELOG.md