Add cargo xtask rust-analyzer

[mkeeter]

This PR adds cargo xtask rust-analyzer, which points rust-analyzer at a particular (manifest, task) tuple (set by a CLI argument). It can be used as a drop-in replacement in your editor, to get LSP goodness within the Hubris build system.

[jamesmunns]

Suggested change

	.nvim.lua
	.nvim.lua
	.zed/settings.json

[jamesmunns]

This definitely works better for me in Zed, there are still some hiccups, I'll try to enumerate them a bit better once I've gotten a better chance to take this for a spin.

Looking at the logs, I see some weirdness: https://gist.github.com/jamesmunns/59c51489e6e62676bef118514a3fddbf

Some of this is attempting to build crates that aren't relevant for cosmo+control_plane_agent, e.g. task-attest.

There are some recurring errors that seem odd to me, like:

  Error: app.toml missing task config section [tasks.control_plane_agent.config]

And also:

Error: reading env var $HUBRIS_KCONFIG

That all being said, I am able to use rust-analyzer in the control-plane-agent task, as well as seemingly other cosmo-relevant tasks.

For context, this is my current .zed/settings.json:

// Folder-specific settings
//
// For a full list of overridable settings, and general information on folder-specific settings,
// see the documentation: https://zed.dev/docs/configuring-zed#settings-files
{
  "lsp": {
    // Specify the LSP name as a key here.
    "rust-analyzer": {
      // // A special flag for rust-analyzer integration, to use server-provided tasks
      // enable_lsp_tasks": true,
      "binary": {
        "path": "cargo",
        "arguments": [
          "run",
          "-pxtask",
          "--",
          "rust-analyzer",
          "--log",
          "./target/xtask-ra.log",
          "./app/cosmo/rev-b-dev.toml:control_plane_agent",
        ],
      },
      // These initialization options are merged into Zed's defaults
      "initialization_options": {
        "check": {
          "command": "clippy", // rust-analyzer.check.command (default: "check")
        },
        "cargo": {
          "targetDir": "target",
        },
      },
    },
  },
}

[jamesmunns]

Happy to do a follow-on PR to document setting up Zed as well.

[mkeeter]

I pushed a fix to set check { workspace: false }, which should reduce some of the chattiness (because it will only run cargo check for the package being edited).