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/admin_dashboard.html

@@ -7,8 +7,8 @@
         <p class="text-muted">System management and user administration.</p>
     </div>
     <div class="col-md-4 text-end">
-        <a href="{{ url_for('admin_spend_report') }}" class="btn btn-outline-primary me-2"><i class="fas fa-chart-line me-2"></i>Spend Report</a>
-        <a href="{{ url_for('index') }}" class="btn btn-outline-secondary">Back to Dashboard</a>
+        <a href="{{ url_for('admin.admin_spend_report') }}" class="btn btn-outline-primary me-2"><i class="fas fa-chart-line me-2"></i>Spend Report</a>
+        <a href="{{ url_for('project.index') }}" class="btn btn-outline-secondary">Back to Dashboard</a>
     </div>
 </div>
 
@@ -41,7 +41,7 @@
                                 <td>
                                     {% if u.id != current_user.id %}
                                     <form action="/admin/user/{{ u.id }}/delete" method="POST" onsubmit="return confirm('Delete user {{ u.username }} and ALL their projects? This cannot be undone.');">
-                                        <a href="{{ url_for('impersonate_user', user_id=u.id) }}" class="btn btn-sm btn-outline-dark me-1" title="Impersonate User">
+                                        <a href="{{ url_for('admin.impersonate_user', user_id=u.id) }}" class="btn btn-sm btn-outline-dark me-1" title="Impersonate User">
                                             <i class="fas fa-user-secret"></i>
                                         </a>
                                         <button class="btn btn-sm btn-outline-danger" title="Delete User"><i class="fas fa-trash"></i></button>
@@ -67,7 +67,7 @@
             </div>
             <div class="card-body">
                 <p class="text-muted small">Manage global AI writing rules and banned words.</p>
-                <a href="{{ url_for('admin_style_guidelines') }}" class="btn btn-outline-primary w-100"><i class="fas fa-spell-check me-2"></i>Edit Style Guidelines</a>
+                <a href="{{ url_for('admin.admin_style_guidelines') }}" class="btn btn-outline-primary w-100"><i class="fas fa-spell-check me-2"></i>Edit Style Guidelines</a>
             </div>
         </div>