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/pattern-sleep.md

@@ -0,0 +1,52 @@
+---
+title: Use Durable Sleep for Delayed Execution
+impact: MEDIUM
+impactDescription: Enables reliable scheduling across restarts
+tags: pattern, sleep, delay, durable, schedule
+---
+
+## Use Durable Sleep for Delayed Execution
+
+Use `dbos.Sleep` for durable delays within workflows. The wakeup time is stored in the database, so the sleep survives restarts.
+
+**Incorrect (non-durable sleep):**
+
+```go
+func delayedTask(ctx dbos.DBOSContext, input string) (string, error) {
+	// time.Sleep is not durable - lost on restart!
+	time.Sleep(60 * time.Second)
+	result, err := dbos.RunAsStep(ctx, doWork, dbos.WithStepName("doWork"))
+	return result, err
+}
+```
+
+**Correct (durable sleep):**
+
+```go
+func delayedTask(ctx dbos.DBOSContext, input string) (string, error) {
+	// Durable sleep - survives restarts
+	_, err := dbos.Sleep(ctx, 60*time.Second)
+	if err != nil {
+		return "", err
+	}
+	result, err := dbos.RunAsStep(ctx, doWork, dbos.WithStepName("doWork"))
+	return result, err
+}
+```
+
+`dbos.Sleep` takes a `time.Duration`. It returns the remaining sleep duration (zero if completed normally).
+
+Use cases:
+- Scheduling tasks to run in the future
+- Implementing retry delays
+- Delays spanning hours, days, or weeks
+
+```go
+func scheduledTask(ctx dbos.DBOSContext, task string) (string, error) {
+	// Sleep for one week
+	dbos.Sleep(ctx, 7*24*time.Hour)
+	return processTask(task)
+}
+```
+
+Reference: [Durable Sleep](https://docs.dbos.dev/golang/tutorials/workflow-tutorial#durable-sleep)