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/queue-deduplication.md

@@ -0,0 +1,51 @@
+---
+title: Deduplicate Queued Workflows
+impact: HIGH
+impactDescription: Prevents duplicate work and resource waste
+tags: queue, deduplication, duplicate, idempotent
+---
+
+## Deduplicate Queued Workflows
+
+Use deduplication IDs to ensure only one workflow with a given ID is active in a queue at a time.
+
+**Incorrect (duplicate workflows possible):**
+
+```python
+queue = Queue("user_tasks")
+
+@app.post("/process/{user_id}")
+def process_for_user(user_id: str):
+    # Multiple requests = multiple workflows for same user!
+    queue.enqueue(process_workflow, user_id)
+```
+
+**Correct (deduplicated by user):**
+
+```python
+from dbos import Queue, SetEnqueueOptions
+from dbos import error as dboserror
+
+queue = Queue("user_tasks")
+
+@app.post("/process/{user_id}")
+def process_for_user(user_id: str):
+    with SetEnqueueOptions(deduplication_id=user_id):
+        try:
+            handle = queue.enqueue(process_workflow, user_id)
+            return {"workflow_id": handle.get_workflow_id()}
+        except dboserror.DBOSQueueDeduplicatedError:
+            return {"status": "already processing"}
+```
+
+Deduplication behavior:
+- If a workflow with the same deduplication ID is `ENQUEUED` or `PENDING`, new enqueue raises `DBOSQueueDeduplicatedError`
+- Once the workflow completes, a new workflow with the same ID can be enqueued
+- Deduplication is per-queue (same ID can exist in different queues)
+
+Use cases:
+- One active task per user
+- Preventing duplicate job submissions
+- Rate limiting by entity
+
+Reference: [Queue Deduplication](https://docs.dbos.dev/python/tutorials/queue-tutorial#deduplication)