refactor: move all project folders into projects/ subdirectory

This change reorganizes the repository structure to keep the root directory
clean. All 15 project folders are now nested under projects/, alongside
infrastructure directories (agents/, templates/, deliverables/, rag/, skills/).

This allows the repository to grow without polluting the core service directories.

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

templates/book_chapter.yml

@@ -38,6 +38,11 @@ steps:
       PROSE STYLE GUIDE: {prose_style}
       TARGET CHAPTER LENGTH: ~{chapter_target_words} words
 
+      CONTINUITY GUARDRAILS:
+        - Use ONLY the outline / character bible and the immediately previous chapter for continuity.
+        - Ignore future chapters, editorial reviews, roundtables, polish drafts, and any non-chapter artifacts.
+        - Never pull facts from a deliverable whose filename indicates a later chapter than {chapter_ref}.
+
       ⚠️ CRITICAL: Your task name tells you EXACTLY which chapter to write.
       Look at the CURRENT MESSAGE — write THAT chapter and ONLY that chapter.
       Do NOT write Chapter 1 unless the message explicitly says "Chapter 1".