feat: add DBOS skills for TypeScript, Python, and Go (#94)

Add three DBOS SDK skills with reference documentation for building
reliable, fault-tolerant applications with durable workflows.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

skills/dbos-python/references/test-fixtures.md

@@ -0,0 +1,63 @@
+---
+title: Use Proper Test Fixtures for DBOS
+impact: LOW-MEDIUM
+impactDescription: Ensures clean state between tests
+tags: testing, pytest, fixtures, reset
+---
+
+## Use Proper Test Fixtures for DBOS
+
+Use pytest fixtures to properly reset DBOS state between tests.
+
+**Incorrect (no reset between tests):**
+
+```python
+def test_workflow_one():
+    DBOS.launch()
+    result = my_workflow()
+    assert result == "expected"
+
+def test_workflow_two():
+    # DBOS state from previous test!
+    result = another_workflow()
+```
+
+**Correct (reset fixture):**
+
+```python
+import pytest
+import os
+from dbos import DBOS, DBOSConfig
+
+@pytest.fixture()
+def reset_dbos():
+    DBOS.destroy()
+    config: DBOSConfig = {
+        "name": "test-app",
+        "database_url": os.environ.get("TESTING_DATABASE_URL"),
+    }
+    DBOS(config=config)
+    DBOS.reset_system_database()
+    DBOS.launch()
+    yield
+    DBOS.destroy()
+
+def test_workflow_one(reset_dbos):
+    result = my_workflow()
+    assert result == "expected"
+
+def test_workflow_two(reset_dbos):
+    # Clean DBOS state
+    result = another_workflow()
+    assert result == "other_expected"
+```
+
+The fixture:
+1. Destroys any existing DBOS instance
+2. Creates fresh configuration
+3. Resets the system database
+4. Launches DBOS
+5. Yields for test execution
+6. Cleans up after test
+
+Reference: [Testing DBOS](https://docs.dbos.dev/python/tutorials/testing)