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-patching.md

@@ -0,0 +1,86 @@
+---
+title: Use Patching for Safe Workflow Upgrades
+impact: LOW
+impactDescription: Safely deploy breaking workflow changes without disrupting in-progress workflows
+tags: advanced, patching, upgrade, breaking-change
+---
+
+## Use Patching for Safe Workflow Upgrades
+
+Use `dbos.Patch` to safely deploy breaking changes to workflow code. Breaking changes alter which steps run or their order, which can cause recovery failures.
+
+**Incorrect (breaking change without patching):**
+
+```go
+// BEFORE: original workflow
+func myWorkflow(ctx dbos.DBOSContext, input string) (string, error) {
+	result, _ := dbos.RunAsStep(ctx, foo, dbos.WithStepName("foo"))
+	_, _ = dbos.RunAsStep(ctx, bar, dbos.WithStepName("bar"))
+	return result, nil
+}
+
+// AFTER: breaking change - recovery will fail for in-progress workflows!
+func myWorkflow(ctx dbos.DBOSContext, input string) (string, error) {
+	result, _ := dbos.RunAsStep(ctx, baz, dbos.WithStepName("baz")) // Changed step
+	_, _ = dbos.RunAsStep(ctx, bar, dbos.WithStepName("bar"))
+	return result, nil
+}
+```
+
+**Correct (using patch):**
+
+```go
+func myWorkflow(ctx dbos.DBOSContext, input string) (string, error) {
+	useBaz, err := dbos.Patch(ctx, "use-baz")
+	if err != nil {
+		return "", err
+	}
+	var result string
+	if useBaz {
+		result, _ = dbos.RunAsStep(ctx, baz, dbos.WithStepName("baz")) // New workflows
+	} else {
+		result, _ = dbos.RunAsStep(ctx, foo, dbos.WithStepName("foo")) // Old workflows
+	}
+	_, _ = dbos.RunAsStep(ctx, bar, dbos.WithStepName("bar"))
+	return result, nil
+}
+```
+
+`dbos.Patch` returns `true` for new workflows and `false` for workflows that started before the patch.
+
+**Deprecating patches (after all old workflows complete):**
+
+```go
+func myWorkflow(ctx dbos.DBOSContext, input string) (string, error) {
+	dbos.DeprecatePatch(ctx, "use-baz") // Always takes the new path
+	result, _ := dbos.RunAsStep(ctx, baz, dbos.WithStepName("baz"))
+	_, _ = dbos.RunAsStep(ctx, bar, dbos.WithStepName("bar"))
+	return result, nil
+}
+```
+
+**Removing patches (after all workflows using DeprecatePatch complete):**
+
+```go
+func myWorkflow(ctx dbos.DBOSContext, input string) (string, error) {
+	result, _ := dbos.RunAsStep(ctx, baz, dbos.WithStepName("baz"))
+	_, _ = dbos.RunAsStep(ctx, bar, dbos.WithStepName("bar"))
+	return result, nil
+}
+```
+
+Lifecycle: `Patch()` → deploy → wait for old workflows → `DeprecatePatch()` → deploy → wait → remove patch entirely.
+
+**Required configuration** — patching must be explicitly enabled:
+
+```go
+ctx, _ := dbos.NewDBOSContext(context.Background(), dbos.Config{
+	AppName:        "my-app",
+	DatabaseURL:    os.Getenv("DBOS_SYSTEM_DATABASE_URL"),
+	EnablePatching: true, // Required for dbos.Patch and dbos.DeprecatePatch
+})
+```
+
+Without `EnablePatching: true`, calls to `dbos.Patch` and `dbos.DeprecatePatch` will fail.
+
+Reference: [Patching](https://docs.dbos.dev/golang/tutorials/upgrading-workflows#patching)