ADR 0001 app factory

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0001. Flask app-factory pattern

Status

Accepted.

Context

The app must run in several modes (local dev, production via Gunicorn, and tests) and be importable by both run.py and wsgi.py without side effects at import time.

Decision

Use create_app(config_name) that builds and configures a fresh app per call. Extensions (SQLAlchemy, Login, Bcrypt, Limiter, CSRF) are module-level singletons initialized inside the factory.

Consequences

• Clean separation of config environments.
• Tests build an isolated in-memory app.
• Blueprints register in one place; new features are additive.