Add complete Ouroboros trading system with TDD test suite

Implement the full autonomous trading agent architecture:
- KIS broker with async API, token refresh, leaky bucket rate limiter, and hash key signing
- Gemini-powered decision engine with JSON parsing and confidence threshold enforcement
- Risk manager with circuit breaker (-3% P&L) and fat finger protection (30% cap)
- Evolution engine for self-improving strategy generation via failure analysis
- 35 passing tests written TDD-first covering risk, broker, and brain modules
- CI/CD pipeline, Docker multi-stage build, and AI agent context docs

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

.github/workflows/ci.yml

@@ -0,0 +1,39 @@
+name: CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Python 3.11
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+
+      - name: Install dependencies
+        run: pip install ".[dev]"
+
+      - name: Lint
+        run: ruff check src/ tests/
+
+      - name: Type check
+        run: mypy src/ --strict
+        continue-on-error: true
+
+      - name: Run tests with coverage
+        run: pytest -v --cov=src --cov-report=term-missing --cov-fail-under=80
+
+      - name: Upload coverage
+        if: always()
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-report
+          path: htmlcov/