fix(lsp): pyright server ignores a project-local pyright-langserver in node_modules/.bin #147

Problem

PyrightServer.spawn (packages/lsp/src/server/pyright.ts) has only two steps: a pyright-langserver on PATH, then the pinned bunx fallback from #146. It never looks for a project-local install:

const pyright = Bun.which('pyright-langserver', { PATH: process.env.PATH ?? '' })
if (!pyright) {
  // bunx -p pyright@1.1.414 pyright-langserver --stdio
}

The npm package pyright is a common devDependency, often added so CI can run npx pyright. Its pyright-langserver bin lands in node_modules/.bin, which is not on PATH outside an npm script. So for a project that pins pyright locally:

• With no global install, the server ignores the project's copy. It runs bunx, which downloads pyright 1.1.414 from the registry. That needs the network and can be a different version from the one the project pins.
• With a global install, the server uses that copy instead of the project's version.

Either way the editor's diagnostics can differ from what the project's own pyright run reports.

The other npm-distributed servers check the project first:

Expected

Lookup order: project-local, then PATH, then bunx.

const pyright = findPackageBin(root, 'pyright', 'pyright-langserver')
  ?? Bun.which('pyright-langserver', { PATH: process.env.PATH ?? '' })

• Walk up from the root, as typescript.ts does, rather than checking only <root>/node_modules. Pyright's root comes from pyproject.toml, setup.py, requirements.txt or pyrightconfig.json. In a mixed repo the Python project is often a subdirectory such as backend/, while package.json and node_modules sit at the repository root. A <root>/node_modules/.bin check like biome.ts's would miss that layout.
• findPackageBin and resolvePackageBin are private to typescript.ts today. Moving them to utils.ts lets both servers share them.
• Check existence only; don't probe the binary. pyright-langserver has no --version flag (it errors with "Connection input stream is not set"), so runsVersion can't vet it.

Tests

Add these to the PyrightServer fallback describe in packages/lsp/test/unit/server.test.ts, using spawnServerWith / recorder:

• Project-local wins: prefer a project-local pyright-langserver over one on PATH and over bunx. Expect local --stdio.
• Walk-up: find a node_modules in a parent of the root, for example a root at <tmp>/backend with node_modules at <tmp>.
• Shim ownership: ignore a node_modules/.bin/pyright-langserver shim that doesn't belong to the pyright package. This applies only if resolvePackageBin is reused.

Notes

• Follow-up to fix(lsp): pyright bunx fallback requests a nonexistent npm package, is unpinned, and never detects a missing bunx #137 / fix(lsp): run a pinned pyright in the pyright bunx fallback #146. fix(lsp): pyright bunx fallback requests a nonexistent npm package, is unpinned, and never detects a missing bunx #137 noted this gap as out of scope.
• Out of scope: handling a broken mise shim on PATH. That needs a probe other than --version.