Add Creative Writing expansion pack (#414)

* Add Creative Writing expansion pack
- 10 specialized writing agents for fiction and narrative design
- 8 complete workflows (novel, screenplay, short story, series)
- 27 quality checklists for genre and technical validation
- 22 writing tasks covering full creative process
- 8 professional templates for structured writing
- KDP publishing integration support

* Fix bmad-creative-writing expansion pack formatting and structure

- Convert all agents to standard BMAD markdown format with embedded YAML
- Add missing core dependencies (create-doc, advanced-elicitation, execute-checklist)
- Add bmad-kb.md customized for creative writing context
- Fix agent dependency references to only include existing files
- Standardize agent command syntax and activation instructions
- Clean up agent dependencies for beta-reader, dialog-specialist, editor, genre-specialist, narrative-designer, and world-builder

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Co-authored-by: Brian <bmadcode@gmail.com>

expansion-packs/bmad-creative-writing/workflows/novel-snowflake-workflow.yaml

@@ -0,0 +1,69 @@
+---
+workflow:
+  id: novel-snowflake-workflow
+  name: Snowflake Novel Workflow
+  description: >-
+    10‑step Snowflake Method culminating in professional critic review.
+  phases:
+    premise:
+      - agent: plot-architect
+        task: brainstorm-premise
+        output: premise.txt
+    paragraph:
+      - agent: plot-architect
+        task: expand-premise
+        input: premise.txt
+        output: premise-paragraph.md
+    characters:
+      - agent: character-psychologist
+        task: develop-character
+        input: premise-paragraph.md
+        output: character-summaries.md
+    synopsis:
+      - agent: plot-architect
+        task: expand-synopsis
+        input: premise-paragraph.md
+        output: synopsis.md
+    deep-character:
+      - agent: character-psychologist
+        task: character-depth-pass
+        input: character-summaries.md
+        output: characters.md
+    scene-list:
+      - agent: plot-architect
+        task: generate-scene-list
+        input:
+          - synopsis.md
+          - characters.md
+        output: scene-list.md
+    outline:
+      - agent: plot-architect
+        task: outline-scenes
+        input: scene-list.md
+        output: snowflake-outline.md
+    drafting:
+      - agent: editor
+        task: create-draft-section
+        input: snowflake-outline.md
+        repeat: per-chapter
+        output: draft-manuscript.md
+    polish:
+      - agent: beta-reader
+        task: provide-feedback
+        input: draft-manuscript.md
+        output: beta-notes.md
+      - agent: editor
+        task: incorporate-feedback
+        input:
+          - draft-manuscript.md
+          - beta-notes.md
+        output: final-manuscript.md
+    critique:
+      - agent: book-critic
+        task: critical-review
+        input: final-manuscript.md
+        output: critic-review.md
+  completion_criteria:
+    - critic-review.md exists
+...
+