Implement core services for MVP-1 Personal Tracker CLI

Services implemented:
- session_service: Active session management (get/set/clear, validation)
- project_service: Project CRUD and directory structure
- note_service: Note handling and consolidation
- heuristics_service: Rule-based suggestions
- summary_service: Heuristic summary generation

pyproject.toml

@@ -0,0 +1,22 @@
+[project]
+name = "tracker"
+version = "0.1.0"
+description = "Personal project tracker CLI with Markdown-based persistence"
+readme = "README.md"
+requires-python = ">=3.11"
+dependencies = [
+    "typer[all]>=0.12.0",
+    "pyyaml>=6.0",
+    "jinja2>=3.1.0",
+    "pydantic>=2.0",
+]
+
+[project.optional-dependencies]
+git = ["gitpython"]
+
+[project.scripts]
+tracker = "tracker.cli.main:app"
+
+[build-system]
+requires = ["setuptools>=61.0"]
+build-backend = "setuptools.build_meta"