feat(astrolabe): add Nextcloud App Store deployment automation

Add complete CI/CD pipeline for automated Astrolabe app releases:
- GitHub Actions workflow for build, sign, and publish
- Makefile for app store package creation
- Version synchronization between info.xml and package.json
- CHANGELOG.md with v0.1.0 release notes

feat: configure commitizen monorepo with independent versioning

Enable independent versioning for three components using scope-based commits:
- MCP Server (feat(mcp) or unscoped): v* tags, updates pyproject.toml + Chart.yaml:appVersion
- Helm Chart (feat(helm)): nextcloud-mcp-server-* tags, updates Chart.yaml:version
- Astrolabe App (feat(astrolabe)): astrolabe-v* tags, updates info.xml + package.json

Changes:
- Add .cz.toml configs for Astrolabe and Helm chart
- Update root pyproject.toml with scope filtering and tag ignores
- Create bump helper scripts (bump-mcp.sh, bump-helm.sh, bump-astrolabe.sh)
- Add CONTRIBUTING.md with version management documentation
- Create component-specific changelogs
- Configure appVersion/version separation for Helm chart

This allows each component to release independently while maintaining
proper version tracking and changelog generation.

third_party/astrolabe/.cz.toml

@@ -0,0 +1,25 @@
+[tool.commitizen]
+name = "cz_conventional_commits"
+version = "0.1.0"
+tag_format = "astrolabe-v$version"
+version_scheme = "pep440"
+update_changelog_on_bump = true
+major_version_zero = true
+
+# Update Astrolabe-specific files only
+version_files = [
+    "appinfo/info.xml:version",
+    "package.json:version"
+]
+
+# Ignore tags from other components
+ignored_tag_formats = [
+    "v*",                      # MCP server tags
+    "nextcloud-mcp-server-*",  # Helm chart tags
+]
+
+# Filter commits by scope
+[tool.commitizen.customize]
+changelog_pattern = "^(feat|fix|docs|refactor|perf|test|build|ci|chore)\\(astrolabe\\)(!)?:"
+schema_pattern = "^(feat|fix|docs|refactor|perf|test|build|ci|chore)\\(astrolabe\\)(!)?:\\s.+"
+message_template = "{{change_type}}(astrolabe): {{message}}"