fix: stop chapter_production from dispatching project_index mid-book

- Remove project_index dispatch from chapter_production.yml entirely.
  chapter_production should ONLY dispatch book_chapter. The project_index
  dispatch belongs to book_editorial (which already handles it correctly).
  This was the root cause of the CLM hallucination cascade:
    pulse_check -> project_review -> chapter_production -> project_index -> marketing_campaign (infinite loop)

- Add clm_dispatch_gate guard in project_index.yml. project_index now checks
  whether its task message is a real book-complete signal or a generic/none
  message. If gate is 'skip', clm_dispatch_content is 'none' and the enqueue
  call returns gracefully (optional: true). Only fires when triggered by
  book_editorial with a legitimate completion message.

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

templates/chapter_production.yml

@@ -108,25 +108,6 @@ steps:
       task_type: "book_chapter"
       content: "{chapter_dispatch_message}"
 
-  # If COMPLETE, dispatch project_index to compile the manuscript and signal book done
-  - type: think
-    max_tokens: 50
-    output_key: index_dispatch_message
-    hint: |
-      Read production_status above.
-      If production_status is COMPLETE, output exactly:
-        Compile the manuscript index for {project.name}. All chapters are polished and complete.
-      If production_status is NEEDS_CHAPTER, output exactly: none
-
-  - type: tool
-    action: enqueue_strategy
-    optional: true
-    params:
-      company_slug: "crimson_leaf_publishing"
-      project_slug: "{project.slug}"
-      task_type: "project_index"
-      content: "{index_dispatch_message}"
-
   - type: reply
     target: channel
     channel_name: "crimson_leaf_publishing:live-feed"