[MCP][Dash] Integrate MCP Dashboard via Command Palette
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### Problem to solve
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As of this MR, https://gitlab.com/gitlab-org/editor-extensions/gitlab-lsp/-/merge_requests/2421+, the MCP dashboard is now available to extensions that want to host it.
### Proposal
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Implement the MCP dashboard as a command palette command in VSCode.
### Further details
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### Links / references
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