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/workflow-control.md

@@ -0,0 +1,77 @@
+---
+title: Cancel, Resume, and Fork Workflows
+impact: MEDIUM
+impactDescription: Control running workflows and recover from failures
+tags: workflow, cancel, resume, fork, control
+---
+
+## Cancel, Resume, and Fork Workflows
+
+Use these methods to control workflow execution: stop runaway workflows, retry failed ones, or restart from a specific step.
+
+**Incorrect (expecting immediate cancellation):**
+
+```python
+DBOS.cancel_workflow(workflow_id)
+# Wrong: assuming the workflow stopped immediately
+cleanup_resources()  # May race with workflow still running its current step
+```
+
+**Correct (wait for cancellation to complete):**
+
+```python
+DBOS.cancel_workflow(workflow_id)
+# Cancellation happens at the START of the next step
+# Wait for workflow to actually stop
+handle = DBOS.retrieve_workflow(workflow_id)
+status = handle.get_status()
+while status.status == "PENDING":
+    time.sleep(0.5)
+    status = handle.get_status()
+# Now safe to clean up
+cleanup_resources()
+```
+
+### Cancel
+
+Stop a workflow and remove it from its queue:
+
+```python
+DBOS.cancel_workflow(workflow_id)  # Cancels workflow and all children
+```
+
+### Resume
+
+Restart a stopped workflow from its last completed step:
+
+```python
+# Resume a cancelled or failed workflow
+handle = DBOS.resume_workflow(workflow_id)
+result = handle.get_result()
+
+# Can also bypass queue for an enqueued workflow
+handle = DBOS.resume_workflow(enqueued_workflow_id)
+```
+
+### Fork
+
+Start a new workflow from a specific step of an existing one:
+
+```python
+# Get steps to find the right starting point
+steps = DBOS.list_workflow_steps(workflow_id)
+for step in steps:
+    print(f"Step {step['function_id']}: {step['function_name']}")
+
+# Fork from step 3 (skips steps 1-2, uses their saved results)
+new_handle = DBOS.fork_workflow(workflow_id, start_step=3)
+
+# Fork to run on a new application version (useful for patching bugs)
+new_handle = DBOS.fork_workflow(
+    workflow_id,
+    start_step=3,
+    application_version="2.0.0"
+)
+```
+
+Reference: [Workflow Management](https://docs.dbos.dev/python/tutorials/workflow-management)