feat: Add integration test suite for Position Manager

- Added Jest + ts-jest configuration (jest.config.js)
- Added global test setup with mocks (tests/setup.ts)
- Added trade factory helpers (tests/helpers/trade-factory.ts)
- Added 7 test suites covering Position Manager logic:
  - tp1-detection.test.ts (13 tests)
  - breakeven-sl.test.ts (9 tests)
  - adx-runner-sl.test.ts (18 tests)
  - trailing-stop.test.ts (14 tests)
  - edge-cases.test.ts (18 tests)
  - price-verification.test.ts (13 tests)
  - decision-helpers.test.ts (28 tests)
- Added test documentation (tests/README.md)
- Updated package.json with Jest dependencies and scripts
- All 113 tests pass

Co-authored-by: mindesbunister <32161838+mindesbunister@users.noreply.github.com>

jest.config.js

@@ -0,0 +1,29 @@
+/** @type {import('jest').Config} */
+const config = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  roots: ['<rootDir>/tests'],
+  testMatch: ['**/*.test.ts'],
+  transform: {
+    '^.+\\.tsx?$': ['ts-jest', {
+      useESM: true,
+      tsconfig: {
+        module: 'ESNext',
+        moduleResolution: 'node',
+      },
+    }],
+  },
+  moduleNameMapper: {
+    '^@/(.*)$': '<rootDir>/$1',
+  },
+  setupFilesAfterEnv: ['<rootDir>/tests/setup.ts'],
+  collectCoverageFrom: [
+    'lib/trading/position-manager.ts',
+    'tests/**/*.ts',
+  ],
+  coverageReporters: ['text', 'text-summary', 'html'],
+  verbose: true,
+  testTimeout: 10000,
+}
+
+module.exports = config