Add clients/web/src/components/elements/AppRenderer/hostContext.ts — a pure
utilities module for the MCP Apps host:
- currentTheme(): read the resolved Mantine color scheme from the DOM
- currentStyles(): map the inspector's Mantine/-inspector design tokens to a
McpUiHostStyles snapshot via STYLE_VARIABLE_SOURCES
- measureContainerDimensions(): whole-pixel container measurement
- snapshotHostContext(): assemble the initial McpUiHostContext seed
Wave 1 of the PR #1510 decomposition (#1579). Pure extraction only — the
AppRenderer/AppsScreen/createAppBridgeFactory rewrites belong to Wave 2.
Full unit coverage (100% lines/statements/functions/branches).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01S3fTN8H3R8YV4yUGvZjYnX
5831b5c3d9