feat: wire skills guides into templates, deduplicate Iris RAG

Skills guides wired (all were dead code — no templates declared skills:):
- book_chapter.yml: YAFictionGuide + RomanceFictionGuide + SciFiFictionGuide
- chapter_review.yml: same (Devon, Lane, Cora reviewers now have genre context)
- chapter_roundtable.yml: same (debate participants use genre craft knowledge)
- chapter_polish.yml: same (Iris polishes with full genre guide in context)
- short_story.yml: same
- blog_write.yml: BlogWritingGuide
- recipe_develop.yml: RecipeWritingGuide

All templates updated to include 'skills' in sections list so guides
are injected as SKILLS & GUIDES block in the prompt.

Iris RAG deduplication:
- agents/iris/rag/agent.rag.md: 15 near-identical entries -> 2 canonical
  Entry 1: Bible & Continuity Check requirement
  Entry 2: Editorial assignments (Devon/Lane/Cora with their roles)
  13 duplicates removed

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

templates/chapter_roundtable.yml

@@ -6,6 +6,11 @@ description: >
 
 debug: true
 
+skills:
+  - guides/YAFictionGuide.md
+  - guides/RomanceFictionGuide.md
+  - guides/SciFiFictionGuide.md
+
 participant_prompt:
   - "= identity.md"
 
@@ -17,6 +22,7 @@ sections:
   - project
   - participants
   - participants_prompt
+  - skills
   - message
   - instructions