feat(astrolabe): add Nextcloud PHP app for MCP server management

Adds a native Nextcloud app "Astroglobe" that provides:
- Personal settings: OAuth authorization for background MCP access
- Admin settings: Server status and vector sync monitoring
- API endpoints for MCP server communication

The app uses PKCE OAuth flow to obtain tokens for the MCP server,
enabling features like background vector sync per ADR-018.

Includes:
- PHP app structure (controllers, services, settings)
- Vue.js frontend components
- Docker compose mount configuration
- Installation hook for development testing
- ADR-018 documentation

🤖 Generated with [Claude Code](https://claude.com/claude-code)

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

third_party/astroglobe/tests/phpunit.xml

@@ -0,0 +1,12 @@
+<?xml version="1.0" encoding="utf-8"?>
+<phpunit xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" bootstrap="bootstrap.php" timeoutForSmallTests="900" timeoutForMediumTests="900" timeoutForLargeTests="900" xsi:noNamespaceSchemaLocation="https://schema.phpunit.de/10.4/phpunit.xsd" cacheDirectory=".phpunit.cache">
+	<testsuite name="M C P Server U I Tests">
+		<directory suffix="Test.php">.</directory>
+	</testsuite>
+	<source>
+		<include>
+			<directory suffix=".php">../appinfo</directory>
+			<directory suffix=".php">../lib</directory>
+		</include>
+	</source>
+</phpunit>