feat: Add 6 new Claude Code skills

Skills added:
- 🔐 Secret Scanner: Detect leaked credentials in codebases
- 🏛️ Git Archaeologist: Analyze git history, find bugs
- 💾 Backup Automator: Automated encrypted cloud backups
- 🌐 Domain Manager: Unified DNS management
- 🔒 SSL Guardian: Certificate automation and monitoring
- 📡 Log Sentinel: Log analysis and anomaly detection

All skills include:
- SKILL.md with trigger patterns
- README.md with documentation
- GLM 5 attribution and disclaimer

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

skills/log-sentinel/SKILL.md

@@ -0,0 +1,36 @@
+---
+name: log-sentinel
+description: Use this skill when the user asks to "analyze logs", "monitor logs", "detect anomalies", "log alerting", "setup log monitoring", "check for errors in logs", or mentions analyzing system/application logs.
+version: 1.0.0
+---
+
+# Log Sentinel Skill
+
+Analyzes system and application logs to detect anomalies, errors, security threats, and performance issues.
+
+## What It Detects
+
+- **Security Threats**: Brute force, intrusion attempts
+- **System Issues**: OOM events, disk warnings, crashes
+- **Application Errors**: HTTP 500, database failures
+
+## Quick Commands
+
+```bash
+# Find errors in syslog
+grep -i "error\|fail\|critical" /var/log/syslog | tail -50
+
+# Failed SSH logins
+grep "Failed password" /var/log/auth.log | awk '{print $(NF-3)}' | sort | uniq -c | sort -nr
+
+# Real-time monitoring
+tail -f /var/log/syslog | grep --line-buffered -i "error"
+```
+
+## Usage
+
+```
+"Analyze system logs for errors"
+"Check for brute force attempts"
+"Setup log alerting for this server"
+```