refactor: consolidate MCP integration to unified gateway

**Changes**:
- Remove individual MCP server docs (superclaude/mcp/*.md)
- Remove MCP server configs (superclaude/mcp/configs/*.json)
- Delete MCP docs component (setup/components/mcp_docs.py)
- Simplify installer (setup/core/installer.py)
- Update components for unified gateway approach

**Rationale**:
- Unified gateway (airis-mcp-gateway) provides all MCP servers
- Individual docs/configs no longer needed (managed centrally)
- Reduces maintenance burden and file count
- Simplifies installation process

**Files Removed**: 17 MCP files (docs + configs)
**Installer Changes**: Removed legacy MCP installation logic

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

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

setup/cli/commands/update.py

@@ -389,9 +389,6 @@ def perform_update(
             if summary.get("updated"):
                 logger.info(f"Updated components: {', '.join(summary['updated'])}")
 
-            if summary.get("backup_path"):
-                logger.info(f"Backup created: {summary['backup_path']}")
-
         else:
             logger.error(f"Update completed with errors in {duration:.1f} seconds")