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/advanced-versioning.md

@@ -0,0 +1,62 @@
+---
+title: Use Versioning for Blue-Green Deployments
+impact: LOW
+impactDescription: Enables safe deployment of new code versions alongside old ones
+tags: advanced, versioning, blue-green, deployment
+---
+
+## Use Versioning for Blue-Green Deployments
+
+Set `ApplicationVersion` in configuration to tag workflows with a version. DBOS only recovers workflows matching the current application version, preventing code mismatches during recovery.
+
+**Incorrect (deploying new code that breaks in-progress workflows):**
+
+```go
+ctx, _ := dbos.NewDBOSContext(context.Background(), dbos.Config{
+	AppName:     "my-app",
+	DatabaseURL: os.Getenv("DBOS_SYSTEM_DATABASE_URL"),
+	// No version set - version auto-computed from binary hash
+	// Old workflows will be recovered with new code, which may break
+})
+```
+
+**Correct (versioned deployment):**
+
+```go
+ctx, _ := dbos.NewDBOSContext(context.Background(), dbos.Config{
+	AppName:            "my-app",
+	DatabaseURL:        os.Getenv("DBOS_SYSTEM_DATABASE_URL"),
+	ApplicationVersion: "2.0.0",
+})
+```
+
+By default, the application version is automatically computed from a SHA-256 hash of the executable binary. Set it explicitly for more control.
+
+**Blue-green deployment strategy:**
+
+1. Deploy new version (v2) alongside old version (v1)
+2. Direct new traffic to v2 processes
+3. Let v1 processes "drain" (complete in-progress workflows)
+4. Check for remaining v1 workflows:
+
+```go
+oldWorkflows, _ := dbos.ListWorkflows(ctx,
+	dbos.WithAppVersion("1.0.0"),
+	dbos.WithStatus([]dbos.WorkflowStatusType{dbos.WorkflowStatusPending}),
+)
+```
+
+5. Once all v1 workflows are complete, retire v1 processes
+
+**Fork to new version (for stuck workflows):**
+
+```go
+// Fork a workflow from a failed step to run on the new version
+handle, _ := dbos.ForkWorkflow[string](ctx, dbos.ForkWorkflowInput{
+	OriginalWorkflowID: workflowID,
+	StartStep:          failedStepID,
+	ApplicationVersion: "2.0.0",
+})
+```
+
+Reference: [Versioning](https://docs.dbos.dev/golang/tutorials/upgrading-workflows#versioning)