docs: add system prompts official sources (Anthropic + community analyses)

- Add System Prompt Contents section in architecture.md (line 300-326)
  - Official Anthropic sources (Tier 1, 100% confidence)
  - Community analyses (Simon Willison, PromptHub)
  - Claude.ai vs API vs Code CLI distinctions

- Update reference.yaml with 4 new system prompts entries
  - system_prompts_official, willison_analysis, prompthub, architecture

- Create resource evaluation: system-prompts-official-vs-community.md
  - Score evolution: 4/5 → 3/5 → 2/5 (after Perplexity fact-check)
  - Decision: Do not integrate x1xhlol repository (redundant)
  - Use official Anthropic sources instead

- Create watchlist for non-integrated resources
  - claudedocs/resource-evaluations/watch-list.md (gitignored)
  - Re-evaluation triggers: Q2 2026 or if 10+ user requests

Related evaluation: docs/resource-evaluations/system-prompts-official-vs-community.md

Co-Authored-By: Claude Sonnet 4.5 <noreply@anthropic.com>

docs/resource-evaluations/README.md

@@ -50,8 +50,9 @@ Les documents de travail bruts (prompts Perplexity, audits clients) restent dans
 | **UML & OOP Diagrams** | 3/5 | **3/5** | ✅ Mention | [uml-oop-diagrams.md](./uml-oop-diagrams.md) |
 | **Vibe Coding Level 2** (Rusitschka) | 4/5 | **4/5** | ✅ Intégré (workflows) | [vibe-coding-rusitschka.md](./vibe-coding-rusitschka.md) |
 | **Peter Wooldridge** (Productivity Stack) | 2/5 | **3/5** | ✅ Practitioner Insights | [wooldridge-productivity-stack.md](./wooldridge-productivity-stack.md) |
+| **System Prompts** (Official vs Community) | 4/5 | **2/5** | ⚠️ Watch only (official sources exist) | [system-prompts-official-vs-community.md](./system-prompts-official-vs-community.md) |
 | **Worktrunk** | 4/5 | **4/5** | ✅ Intégré (workflow) | [worktrunk-evaluation.md](./worktrunk-evaluation.md) |
 
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-**Dernier update**: 2026-01-26 (Migration vers docs/ tracké)
+**Dernier update**: 2026-01-26 (15 évaluations)