fix(astrolabe): address code review feedback

CRITICAL FIXES:
- Fix tag parsing in workflow to strip "astrolabe-v" instead of "v"
  For tag astrolabe-v0.1.0, now correctly extracts "0.1.0"
- Add workflow filtering to only run on astrolabe-v* tags
  Prevents wasting CI resources on MCP/Helm releases

RECOMMENDED IMPROVEMENTS:
- Make Nextcloud server path configurable in Makefile
  Can now override: make appstore server_dir=/path/to/server
- Add dependency validation to Makefile
  Checks for composer, npm, php before building
- Add signing prerequisite validation
  Verifies server/occ, private key, and certificate exist
- Add dependency checks to all bump scripts
  Validates uv is installed before running cz bump

These changes improve local build experience and prevent common
errors with clear error messages and installation guidance.

.github/workflows/appstore-build-publish.yml

@@ -11,6 +11,8 @@ env:
 jobs:
   build-and-publish:
     runs-on: ubuntu-latest
+    # Only run on Astrolabe releases
+    if: startsWith(github.ref, 'refs/tags/astrolabe-v')
 
     steps:
       - name: Checkout code
@@ -19,7 +21,7 @@ jobs:
       - name: Get version from tag
         id: tag
         run: |
-          echo "TAG=${GITHUB_REF#refs/tags/v}" >> $GITHUB_OUTPUT
+          echo "TAG=${GITHUB_REF#refs/tags/astrolabe-v}" >> $GITHUB_OUTPUT
 
       - name: Validate version in info.xml matches tag
         working-directory: ${{ env.APP_DIR }}