refactor(astrolabe): reframe UI as semantic search service

Update all user-facing text to focus on Astroglobe as a semantic
search service for Nextcloud users:

- info.xml: New description focusing on finding content by meaning
- Settings sections: Renamed from "MCP Server" to "Astroglobe"
- Personal settings: Reframed as content indexing controls
- Admin settings: Reframed as semantic search administration
- OAuth flow: Explains semantic search benefits to users

Key messaging changes:
- "MCP Server" → "Astroglobe"
- "Grant Background Access" → "Enable Semantic Search"
- "Vector Sync" → "Content Indexing"
- Focus on user benefits: natural language search, finding by meaning

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

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

third_party/astroglobe/lib/Settings/AdminSection.php

@@ -9,9 +9,9 @@ use OCP\IURLGenerator;
 use OCP\Settings\IIconSection;
 
 /**
- * Admin settings section for MCP Server.
+ * Admin settings section for Astroglobe.
  *
- * Creates a dedicated section in admin settings for MCP-related configuration.
+ * Creates a dedicated section in admin settings for semantic search administration.
  */
 class AdminSection implements IIconSection {
 	private $l;
@@ -26,14 +26,14 @@ class AdminSection implements IIconSection {
 	 * @return string The section ID
 	 */
 	public function getID(): string {
-		return 'mcp';
+		return 'astroglobe';
 	}
 
 	/**
 	 * @return string The translated section name
 	 */
 	public function getName(): string {
-		return $this->l->t('MCP Server');
+		return $this->l->t('Astroglobe');
 	}
 
 	/**