refactor: migrate to DDD architecture with Dishka DI

Complete architectural refactoring from simple MVC to Clean Architecture/DDD pattern:

Domain Layer:

- Add entities (Post, BaseEntity) with business logic

- Add value objects (Title, Content, Slug) with validation

- Add repository interfaces (PostRepository)

- Add domain exceptions

Application Layer:

- Add use cases (CreatePost, GetPost, UpdatePost, DeletePost, ListPosts, PublishPost)

- Add DTOs for data transfer

- Add TransactionManager interface

Infrastructure Layer:

- Add SQLAlchemy models and async database connection

- Add SQLAlchemyPostRepository implementation

- Add Dishka DI container with providers

- Add error handlers and middleware

Presentation Layer:

- Add FastAPI routes with Dishka integration

- Add Pydantic schemas

- Add dependency injection using FromDishka[T]

Other Changes:

- Remove old flat structure (api/, common/, core/, modules/)

- Add hatchling build system for package scripts

- Add blog CLI command

- Update AGENTS.md with new architecture docs

- All 48 tests passing, mypy clean, ruff clean

pyproject.toml

@@ -4,11 +4,21 @@ version = "0.1.0"
 description = "Add your description here"
 readme = "README.md"
 requires-python = ">=3.13"
+
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[tool.hatch.build.targets.wheel]
+packages = ["app"]
 dependencies = [
     "fastapi>=0.136.0",
     "pydantic>=2.13.2",
     "pydantic-settings>=2.14.0",
     "uvicorn>=0.44.0",
+    "sqlalchemy>=2.0.0",
+    "aiosqlite>=0.21.0",
+    "dishka>=1.5.0",
 ]
 
 [dependency-groups]
@@ -35,10 +45,13 @@ types = [
     "mypy>=1.20.1",
 ]
 
+[project.scripts]
+blog = "app.main:main"
+
 [tool.pytest.ini_options]
 asyncio_mode = "auto"
 asyncio_default_fixture_loop_scope = "function"
-addopts = "--cov=src --cov-report=term"
+addopts = "--cov=app --cov-report=term-missing --cov-report=html"
 pythonpath = "."
 testpaths = "tests"
 xfail_strict = true