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>

Dockerfile

@@ -14,11 +14,11 @@ RUN apt-get update && apt-get install -y \
 
 # Copy requirements files
 COPY requirements.txt .
-COPY modules/requirements_web.txt ./modules/
+COPY web/requirements_web.txt ./web/
 
 # Install dependencies
 RUN pip install --no-cache-dir -r requirements.txt
-RUN pip install --no-cache-dir -r modules/requirements_web.txt
+RUN pip install --no-cache-dir -r web/requirements_web.txt
 
 # Copy the rest of the application
 COPY . .
@@ -28,4 +28,4 @@ ENV PYTHONPATH=/app
 EXPOSE 5000
 HEALTHCHECK --interval=30s --timeout=10s --start-period=60s --retries=3 \
     CMD python -c "import urllib.request; urllib.request.urlopen('http://localhost:5000/login')" || exit 1
-CMD ["python", "-m", "modules.web_app"]
+CMD ["python", "-m", "web.app"]