v2.0.0: Modularize project into single-responsibility packages

Replaced monolithic modules/ package with a clean architecture:

- core/       config.py, utils.py
- ai/         models.py (ResilientModel), setup.py (init_models)
- story/      planner.py, writer.py, editor.py, style_persona.py, bible_tracker.py
- marketing/  cover.py, blurb.py, fonts.py, assets.py
- export/     exporter.py
- web/        app.py (Flask factory), db.py, helpers.py, tasks.py, routes/{auth,project,run,persona,admin}.py
- cli/        engine.py (run_generation), wizard.py (BookWizard)

Flask routes split into 5 Blueprints; all templates updated with blueprint-
prefixed url_for() calls. Dockerfile and docker-compose updated to use
web.app entry point and new package paths.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

docker-compose.yml

@@ -18,11 +18,14 @@ services:
       # --- DEVELOPMENT (Code Sync) ---
       # UNCOMMENT these lines only if you are developing and want to see changes instantly.
       # For production/deployment, keep them commented out so the container uses the built image code.
-      # - ./modules:/app/modules
+      # - ./core:/app/core
+      # - ./ai:/app/ai
+      # - ./story:/app/story
+      # - ./marketing:/app/marketing
+      # - ./export:/app/export
+      # - ./web:/app/web
+      # - ./cli:/app/cli
       # - ./templates:/app/templates
-      # - ./main.py:/app/main.py
-      # - ./wizard.py:/app/wizard.py
-      # - ./config.py:/app/config.py
     environment:
       - PYTHONUNBUFFERED=1
       - GOOGLE_APPLICATION_CREDENTIALS=/app/credentials.json