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-golang/references/test-setup.md

@@ -0,0 +1,90 @@
+---
+title: Use Proper Test Setup for DBOS
+impact: LOW-MEDIUM
+impactDescription: Ensures consistent test results with proper DBOS lifecycle management
+tags: testing, go-test, setup, integration, mock
+---
+
+## Use Proper Test Setup for DBOS
+
+DBOS applications can be tested with unit tests (mocking DBOSContext) or integration tests (real Postgres database).
+
+**Incorrect (no lifecycle management between tests):**
+
+```go
+// Tests share state - results are inconsistent!
+func TestOne(t *testing.T) {
+	myWorkflow(ctx, "input")
+}
+func TestTwo(t *testing.T) {
+	// Previous test's state leaks into this test
+	myWorkflow(ctx, "input")
+}
+```
+
+**Correct (unit testing with mocks):**
+
+The `DBOSContext` interface is fully mockable. Use a mocking library like `testify/mock` or `mockery`:
+
+```go
+func TestWorkflow(t *testing.T) {
+	mockCtx := mocks.NewMockDBOSContext(t)
+
+	// Mock RunAsStep to return a canned value
+	mockCtx.On("RunAsStep", mockCtx, mock.Anything, mock.Anything).
+		Return("mock-result", nil)
+
+	result, err := myWorkflow(mockCtx, "input")
+	assert.NoError(t, err)
+	assert.Equal(t, "expected", result)
+
+	mockCtx.AssertExpectations(t)
+}
+```
+
+**Correct (integration testing with Postgres):**
+
+```go
+func setupDBOS(t *testing.T) dbos.DBOSContext {
+	t.Helper()
+	databaseURL := os.Getenv("DBOS_TEST_DATABASE_URL")
+	if databaseURL == "" {
+		t.Skip("DBOS_TEST_DATABASE_URL not set")
+	}
+
+	ctx, err := dbos.NewDBOSContext(context.Background(), dbos.Config{
+		AppName:     "test-" + t.Name(),
+		DatabaseURL: databaseURL,
+	})
+	require.NoError(t, err)
+
+	dbos.RegisterWorkflow(ctx, myWorkflow)
+
+	err = dbos.Launch(ctx)
+	require.NoError(t, err)
+
+	t.Cleanup(func() {
+		dbos.Shutdown(ctx, 10*time.Second)
+	})
+	return ctx
+}
+
+func TestWorkflowIntegration(t *testing.T) {
+	ctx := setupDBOS(t)
+
+	handle, err := dbos.RunWorkflow(ctx, myWorkflow, "test-input")
+	require.NoError(t, err)
+
+	result, err := handle.GetResult()
+	require.NoError(t, err)
+	assert.Equal(t, "expected-output", result)
+}
+```
+
+Key points:
+- Use `t.Cleanup` to ensure `Shutdown` is called after each test
+- Use unique `AppName` per test to avoid collisions
+- Mock `DBOSContext` for fast unit tests without Postgres
+- Use real Postgres for integration tests that verify durable behavior
+
+Reference: [Testing DBOS](https://docs.dbos.dev/golang/tutorials/testing)