refactor: consolidate logging to shared aitbc-core package and upgrade database dependencies

- Upgrade SQLAlchemy to 2.0.47 with asyncio extras in blockchain-node and coordinator-api
- Add asyncpg >=0.29.0 for PostgreSQL async support
- Remove uvloop as optional dependency, make it required >=0.22.0
- Delete duplicate logger.py from blockchain-node (117 lines)
- Refactor coordinator-api logging to use shared aitbc.logging from aitbc-core package
- Add aitbc-core package dependency to coordinator

packages/py/aitbc-core/pyproject.toml

@@ -0,0 +1,20 @@
+[tool.poetry]
+name = "aitbc-core"
+version = "0.1.0"
+description = "AITBC Core Utilities"
+authors = ["AITBC Team <team@aitbc.dev>"]
+readme = "README.md"
+packages = [{include = "aitbc", from = "src"}]
+
+[tool.poetry.dependencies]
+python = "^3.13"
+pydantic = "^2.7.0"
+python-json-logger = "^2.0.7"
+
+[tool.poetry.group.dev.dependencies]
+pytest = "^8.2.0"
+mypy = "^1.19.1"
+
+[build-system]
+requires = ["poetry-core"]
+build-backend = "poetry.core.masonry.api"