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>

core/config.py

@@ -0,0 +1,68 @@
+import os
+from dotenv import load_dotenv
+
+# __file__ is core/config.py; app root is one level up
+_HERE = os.path.dirname(os.path.abspath(__file__))
+BASE_DIR = os.path.dirname(_HERE)
+
+# Ensure .env is loaded from the app root
+load_dotenv(os.path.join(BASE_DIR, ".env"))
+
+def get_clean_env(key, default=None):
+    val = os.getenv(key, default)
+    return val.strip() if val else None
+
+API_KEY = get_clean_env("GEMINI_API_KEY")
+GCP_PROJECT = get_clean_env("GCP_PROJECT")
+GCP_LOCATION = get_clean_env("GCP_LOCATION", "us-central1")
+MODEL_LOGIC_HINT = get_clean_env("MODEL_LOGIC", "AUTO")
+MODEL_WRITER_HINT = get_clean_env("MODEL_WRITER", "AUTO")
+MODEL_ARTIST_HINT = get_clean_env("MODEL_ARTIST", "AUTO")
+MODEL_IMAGE_HINT = get_clean_env("MODEL_IMAGE", "AUTO")
+DEFAULT_BLUEPRINT = "book_def.json"
+
+# --- SECURITY & ADMIN ---
+FLASK_SECRET = get_clean_env("FLASK_SECRET_KEY", "dev-secret-key-change-this")
+ADMIN_USER = get_clean_env("ADMIN_USERNAME")
+ADMIN_PASSWORD = get_clean_env("ADMIN_PASSWORD")
+
+if FLASK_SECRET == "dev-secret-key-change-this":
+    print("⚠️ WARNING: Using default FLASK_SECRET_KEY. This is insecure for production.")
+
+if not API_KEY: raise ValueError("❌ CRITICAL ERROR: GEMINI_API_KEY not found.")
+
+# --- DATA DIRECTORIES ---
+DATA_DIR = os.path.join(BASE_DIR, "data")
+PROJECTS_DIR = os.path.join(DATA_DIR, "projects")
+PERSONAS_DIR = os.path.join(DATA_DIR, "personas")
+PERSONAS_FILE = os.path.join(PERSONAS_DIR, "personas.json")
+FONTS_DIR = os.path.join(DATA_DIR, "fonts")
+
+# --- ENSURE DIRECTORIES EXIST ---
+for d in [DATA_DIR, PROJECTS_DIR, PERSONAS_DIR, FONTS_DIR]:
+    if not os.path.exists(d): os.makedirs(d, exist_ok=True)
+
+# --- AUTHENTICATION ---
+GOOGLE_CREDS = os.getenv("GOOGLE_APPLICATION_CREDENTIALS")
+if GOOGLE_CREDS:
+    if not os.path.isabs(GOOGLE_CREDS):
+        GOOGLE_CREDS = os.path.join(BASE_DIR, GOOGLE_CREDS)
+
+    if os.path.exists(GOOGLE_CREDS):
+        os.environ["GOOGLE_APPLICATION_CREDENTIALS"] = GOOGLE_CREDS
+    else:
+        print(f"⚠️ Warning: GOOGLE_APPLICATION_CREDENTIALS file not found at: {GOOGLE_CREDS}")
+
+# --- DEFINITIONS ---
+LENGTH_DEFINITIONS = {
+    "01": {"label": "Chapter Book", "words": "5,000 - 10,000", "chapters": 10, "depth": 1},
+    "1": {"label": "Flash Fiction", "words": "500 - 1,500", "chapters": 1, "depth": 1},
+    "2": {"label": "Short Story", "words": "5,000 - 10,000", "chapters": 5, "depth": 1},
+    "2b": {"label": "Young Adult", "words": "50,000 - 70,000", "chapters": 25, "depth": 3},
+    "3": {"label": "Novella", "words": "20,000 - 40,000", "chapters": 15, "depth": 2},
+    "4": {"label": "Novel", "words": "60,000 - 80,000", "chapters": 30, "depth": 3},
+    "5": {"label": "Epic", "words": "100,000+", "chapters": 50, "depth": 4}
+}
+
+# --- SYSTEM ---
+VERSION = "1.4.0"