feat: patterns/ directory + skill-impact tracker (WikiSkill-inspired)

- New patterns/ directory with 7 initial failure-mode patterns (PAT-001..007)
- skill-impact.md audit trail for skill modifications
- _template.md for future pattern creation
- index.md updated with Patterns section
- log.md entry for this change
- Inspired by arXiv:2608.27454 (WikiSkill)

index.md

@@ -12,6 +12,7 @@
 | `systems/` | Software-Systeme und Services |
 | `concepts/` | Abstrakte Patterns & Konventionen |
 | `reference/` | Quick-Lookup Tabellen (IPs, Keys, Ports) |
+| `patterns/` | Rekurrente Failure-Mode Patterns + Skill-Impact Tracker |
 
 ## Entities
 - [[entities/infrastructure]] — Physikalische Hardware, Cluster-Übersicht
@@ -42,6 +43,17 @@
 - [[reference/ssh-keys]] — Key → Zweck → Fingerprint
 - [[reference/ports]] — Port → Service → Host
 
+## Patterns
+- [[patterns/_README]] — Konzept und Nutzung des Patterns-Verzeichnisses
+- [[patterns/galera-ddl-deadlock]] — OPTIMIZE TABLE → TOI Deadlock (PAT-001)
+- [[patterns/traefik-reload-unreliable]] — reload unreliable, restart statt reload (PAT-002)
+- [[patterns/1password-rate-limit]] — Account-Level Rate-Limit, ESO stoppen (PAT-003)
+- [[patterns/vfio-gpu-passthrough]] — softdep + DRM blacklist Race Condition (PAT-004)
+- [[patterns/finanzblick-sync-waf]] — POST /sync WAF-blocked, UI Modal Sequence (PAT-005)
+- [[patterns/linkedin-react-input]] — nativeInputSetter, Session Expiry (PAT-006)
+- [[patterns/ceph-ssd-wear-ec-pool]] — EC Pool unusable + SSD Wear-Level (PAT-007)
+- [[patterns/skill-impact]] — Skill Modification Audit Trail
+
 ## Memory Layer Architektur
 | Layer | System | Pfad | Rolle |
 |-------|--------|------|-------|