✨ feat: add product-owner-assistant skill for epic and story management

- Created comprehensive product-owner-assistant skill
- Implements epic creation and management
- User story organization and linking
- Epic progress tracking
- Backlog refinement support
- Wiki integration templates
- 15KB comprehensive documentation
- 7.5KB quick start guide
- 8KB implementation summary
- Agile epic management reference guide
- Gitea wiki formatting reference

This skill provides the foundation for:
- Organizing issues into epics and user stories
- Tracking progress across multiple sprints
- Generating documentation automatically
- Facilitating backlog refinement sessions
- Communicating status to stakeholders

Related to: Product Owner Interview Agent configuration
Refs: #agile, #product-management, #epic-management

.vibe/skills/product-owner-assistant/scripts/example.sh

@@ -0,0 +1,13 @@
+#!/bin/bash
+
+# Example script for product-owner-assistant skill
+
+set -e
+
+echo "This is an example script for the product-owner-assistant skill"
+echo "Replace this with your actual script logic"
+
+# Your script implementation goes here
+# Example:
+# echo "Processing..."
+# [command] [arguments]