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>

templates/persona_edit.html

@@ -8,7 +8,7 @@
                 <h4 class="mb-0">{% if name %}Edit Persona: {{ name }}{% else %}New Persona{% endif %}</h4>
             </div>
             <div class="card-body">
-                <form action="{{ url_for('save_persona') }}" method="POST">
+                <form action="{{ url_for('persona.save_persona') }}" method="POST">
                     <input type="hidden" name="old_name" value="{{ name }}">
                     
                     <div class="mb-3">
@@ -72,7 +72,7 @@
                     </div>
                     
                     <div class="d-flex justify-content-between">
-                        <a href="{{ url_for('list_personas') }}" class="btn btn-outline-secondary">Cancel</a>
+                        <a href="{{ url_for('persona.list_personas') }}" class="btn btn-outline-secondary">Cancel</a>
                         <button type="submit" class="btn btn-primary">Save Persona</button>
                     </div>
                 </form>