CI: run the frontend, graph embed and Switch Bay VS tests

[benjsmith]

CI now runs the tests that came with the Curiosity Engine graph work:

• Frontend Node tests (10): upload-to-vault and agent space helpers.
• CE embed and VS Code graph bridge Node tests (29): sidebar header and workspace name, host shims (sanitising, split routing, replay wiring), embed fetch shim, and the VS Code webview's postMessage bridge, search hits and theme.
• Switch Bay VS: install, compile, and Node tests (20), covering the graph bundle freshness, page edit rules and CE API answers, search hits, and wiki pointer.
• A check that the old in-repo graph viewer stays removed and nothing references it.
• The graph-ce-embed browser test (3): Graph tab hidden without Curiosity Engine, workspace name in the sidebar header, and the sidebar upload button plus canvas mount.

Each step fails on any skipped, missing or extra test, like the existing ones.