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/read_book.html

@@ -7,12 +7,12 @@
         <small class="text-muted">Run #{{ run.id }}</small>
     </div>
     <div>
-        <form action="{{ url_for('sync_book_metadata', run_id=run.id, book_folder=book_folder) }}" method="POST" class="d-inline me-2" onsubmit="return confirm('This will re-scan your manuscript to update the character list and author persona. Continue?');">
+        <form action="{{ url_for('run.sync_book_metadata', run_id=run.id, book_folder=book_folder) }}" method="POST" class="d-inline me-2" onsubmit="return confirm('This will re-scan your manuscript to update the character list and author persona. Continue?');">
             <button type="submit" class="btn btn-outline-info" data-bs-toggle="tooltip" title="Scans your manual edits to update the character database and author writing style. Use this after making significant edits.">
                 <i class="fas fa-sync me-2"></i>Sync Metadata
             </button>
         </form>
-        <a href="{{ url_for('view_run', id=run.id) }}" class="btn btn-outline-secondary">Back to Run</a>
+        <a href="{{ url_for('run.view_run', id=run.id) }}" class="btn btn-outline-secondary">Back to Run</a>
     </div>
 </div>