docs: Add server configuration manual and manpages

[inureyes]

Summary

• Create comprehensive documentation for bssh-server and bssh-keygen
• Add man pages in roff format
• Add deployment guides, security documentation, and audit logging guide

New Documentation Files

Man Pages

File	Section	Description
docs/man/bssh-server.8	8	System administration manual for bssh-server
docs/man/bssh-keygen.1	1	User manual for SSH key generation tool

Guides

File	Description
docs/README.md	Documentation index and quick links
docs/quick-start.md	Getting started guide with installation and first run
docs/container-deployment.md	Docker and Kubernetes deployment guide
docs/security.md	Security best practices and hardening checklist
docs/audit-logging.md	Audit logging setup and SIEM integration

Documentation Coverage

bssh-server(8) Man Page

• All CLI options documented
• All subcommands (run, gen-config, gen-host-key, hash-password, check-config, version)
• Environment variables reference
• Configuration file locations
• Examples for common operations

bssh-keygen(1) Man Page

• All CLI options documented
• Key types (Ed25519, RSA)
• Security considerations
• Examples for various use cases

Quick Start Guide

• Binary installation
• Source installation
• Host key generation
• Basic configuration
• systemd service setup

Container Deployment Guide

• Dockerfile examples
• docker-compose configurations
• Kubernetes manifests (ConfigMap, Secret, Deployment, Service)
• Health check configurations
• Best practices for container deployments

Security Guide

• Authentication security (public key vs password)
• Network security (IP access control)
• Session security (limits, timeouts)
• File transfer security (filtering)
• Host key management
• Hardening checklist

Audit Logging Guide

• Configuration for all exporters (file, OTEL, Logstash)
• Event types and structure
• Log analysis queries
• SIEM integration examples (Splunk, Datadog, Grafana)
• fail2ban integration

Man Page Installation

sudo install -Dm644 docs/man/bssh.1 /usr/share/man/man1/bssh.1
sudo install -Dm644 docs/man/bssh-keygen.1 /usr/share/man/man1/bssh-keygen.1
sudo install -Dm644 docs/man/bssh-server.8 /usr/share/man/man8/bssh-server.8
sudo mandb

Test Plan

• Man pages render correctly with man -l
• All configuration options documented
• All CLI arguments documented
• Examples are accurate and working
• Links between documentation files are valid

Closes #144