feat: set up Python project structure with pyproject.toml

- Add pyproject.toml with core and dev dependencies
- Configure Ruff for linting and formatting
- Configure MyPy for strict type checking
- Configure pytest with asyncio support
- Create src/polymarket_insider_tracker package structure
- Add py.typed marker for PEP 561 compliance
- Add pre-commit hooks configuration
- Add comprehensive .gitignore
- Create test directory structure with basic tests

Closes #25

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

.pre-commit-config.yaml

@@ -0,0 +1,23 @@
+repos:
+  - repo: https://github.com/pre-commit/pre-commit-hooks
+    rev: v4.5.0
+    hooks:
+      - id: trailing-whitespace
+      - id: end-of-file-fixer
+      - id: check-yaml
+      - id: check-added-large-files
+      - id: check-merge-conflict
+
+  - repo: https://github.com/astral-sh/ruff-pre-commit
+    rev: v0.1.9
+    hooks:
+      - id: ruff
+        args: [--fix]
+      - id: ruff-format
+
+  - repo: https://github.com/pre-commit/mirrors-mypy
+    rev: v1.8.0
+    hooks:
+      - id: mypy
+        additional_dependencies:
+          - pydantic>=2.0.0