fix: use correct scoped package name in changeset (#166)

Author: TabishB

.changeset/amazon-q-integration.md

@@ -1,5 +1,5 @@
 ---
-"openspec": minor
+"@fission-ai/openspec": minor
 ---
 
 Add Amazon Q Developer CLI integration. OpenSpec now supports Amazon Q Developer with automatic prompt generation in `.amazonq/prompts/` directory, allowing you to use OpenSpec slash commands with Amazon Q's @-syntax.