Fix version extraction in CI (use sed instead of grep -P)

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Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: Your Name

.github/workflows/ci.yml

@@ -38,7 +38,7 @@ jobs:
       - name: Get version
         id: version
         run: |
-          VERSION=$(grep -oP 'VERSION="\K[^"]+' agent-persona)
+          VERSION=$(sed -n 's/^VERSION="\([^"]*\)".*/\1/p' agent-persona)
           echo "version=$VERSION" >> $GITHUB_OUTPUT
 
       - name: Check if tag exists