Biff 2 database adapter for Datalevin.

Provides a biff.core module that:

  - starts a Datalevin connection
  - implements biff.core's key-value store interface
    (:biff.core/kv-get, :biff.core/kv-set, :biff.core/kv-list)
  - provides :biff.core/wrap-db-snapshot for consistent reads
  - calls :biff.core/on-tx after transactions
  - generates biff.graph resolvers from a Datalevin schema
  - provides biff.fx handlers for queries and transactions

Example:

  (def modules
    [(biff.fx/module)
     (biff.graph/module)
     (biff.datalevin.adapter/module
      {:biff.datalevin/db-path "data/myapp"
       :biff.datalevin/schema my-schema})])

  (def start-order
    [:biff.datalevin/module])

See https://github.com/jacobobryant/biff/blob/master/docs/db-adapters.md

Authentication utilities including password hashing and OAuth support.

Provides patterns for:
- Password-based authentication with bcrypt
- OAuth flows (GitHub, extensible to other providers)

Core system lifecycle management for biff-datalevin.

Provides a simple map-based component system inspired by Biff's architecture.
Components are functions that take a system map and return a modified system map.

Database connection management, transaction helpers, and query utilities.

Provides Biff-style transaction semantics adapted for Datalevin.

Ring middleware for authentication, CSRF protection, and context injection.

Provides Biff-style middleware composition for web applications.

Session management backed by Datalevin.

Provides both direct session management functions and a Ring-compatible
session store implementation.