refactor: extract Astrolabe to separate repository

Astrolabe has been extracted to its own repository at
github.com/cbcoutinho/astrolabe for independent releases.

Changes:
- Replace third_party/astrolabe/ directory with git submodule
- Remove astrolabe-ci.yml and appstore-build-publish.yml workflows
- Remove scripts/bump-astrolabe.sh
- Remove Astrolabe sections from bump-version.yml workflow
- Remove Astrolabe build steps from test.yml CI workflow
- Remove astrolabe volume mount from docker-compose.yml
- Simplify astrolabe install hook to always use app store
- Update CONTRIBUTING.md to reflect two-component monorepo

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

.github/workflows/bump-version.yml

@@ -83,9 +83,9 @@ jobs:
             commit_range="${last_mcp_tag}..HEAD"
           fi
 
-          # Count conventional commits that are NOT scoped to helm or astrolabe
+          # Count conventional commits that are NOT scoped to helm
           mcp_commit_count=$(git log "$commit_range" --oneline --grep="^(feat|fix|docs|refactor|perf|test|build|ci|chore)" -E | \
-            { grep -v "(helm)" || true; } | { grep -v "(astrolabe)" || true; } | wc -l)
+            { grep -v "(helm)" || true; } | wc -l)
 
           MCP_BUMPED=false
           if [ "$mcp_commit_count" -gt 0 ]; then
@@ -115,14 +115,6 @@ jobs:
             BUMPED_COMPONENTS="$BUMPED_COMPONENTS helm"
           fi
 
-          # Bump Astrolabe (scope: astrolabe)
-          echo "Checking Astrolabe for version bump..."
-          if has_commits_since_tag "astrolabe-v" "(feat|fix|docs|refactor|perf|test|build|ci|chore)\(astrolabe\)(!)?:"; then
-            echo "Bumping Astrolabe version..."
-            ./scripts/bump-astrolabe.sh
-            BUMPED_COMPONENTS="$BUMPED_COMPONENTS astrolabe"
-          fi
-
           # Output summary
           if [ -z "$BUMPED_COMPONENTS" ]; then
             echo "No components required version bumps"
@@ -158,10 +150,6 @@ jobs:
                   tag=$(git tag --sort=-creatordate | grep -E '^nextcloud-mcp-server-' | head -n 1)
                   echo "- **Helm Chart**: \`$tag\`" >> $GITHUB_STEP_SUMMARY
                   ;;
-                astrolabe)
-                  tag=$(git tag --sort=-creatordate | grep -E '^astrolabe-v' | head -n 1)
-                  echo "- **Astrolabe**: \`$tag\`" >> $GITHUB_STEP_SUMMARY
-                  ;;
               esac
             done