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/personas.html

@@ -3,7 +3,7 @@
 {% block content %}
 <div class="d-flex justify-content-between align-items-center mb-4">
     <h2><i class="fas fa-users me-2"></i>Author Personas</h2>
-    <a href="{{ url_for('new_persona') }}" class="btn btn-primary"><i class="fas fa-plus me-2"></i>Create New Persona</a>
+    <a href="{{ url_for('persona.new_persona') }}" class="btn btn-primary"><i class="fas fa-plus me-2"></i>Create New Persona</a>
 </div>
 
 <div class="row">
@@ -16,8 +16,8 @@
                 <p class="card-text small">{{ p.bio[:150] }}...</p>
             </div>
             <div class="card-footer bg-white border-top-0 d-flex justify-content-between">
-                <a href="{{ url_for('edit_persona', name=name) }}" class="btn btn-sm btn-outline-primary">Edit</a>
-                <form action="{{ url_for('delete_persona', name=name) }}" method="POST" onsubmit="return confirm('Delete this persona?');">
+                <a href="{{ url_for('persona.edit_persona', name=name) }}" class="btn btn-sm btn-outline-primary">Edit</a>
+                <form action="{{ url_for('persona.delete_persona', name=name) }}" method="POST" onsubmit="return confirm('Delete this persona?');">
                     <button type="submit" class="btn btn-sm btn-outline-danger">Delete</button>
                 </form>
             </div>