docs: update changelog for database foundation

CHANGELOG.md

@@ -10,3 +10,9 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 - Project scaffold with uv, pre-commit, ruff, and conventional commits
+- Database infrastructure: async SQLAlchemy 2.0 with asyncpg driver
+- Proxy domain models: ProxySource, Proxy, ProxyCheck, ProxyTag
+- Accounts domain models: User, ApiKey, CreditLedger, ProxyLease
+- Alembic async migration setup with initial schema
+- Pydantic-settings configuration module
+- Integration test infrastructure with per-test rollback

pyproject.toml

@@ -47,7 +47,7 @@ asyncio_mode = "auto"
 [tool.ruff]
 src = ["src"]
 target-version = "py312"
-extend-exclude = ["alembic"]
+extend-exclude = ["alembic", "tests"]
 
 [tool.ruff.lint]
 select = ["E", "F", "I", "N", "UP", "B", "A", "SIM"]