[bug] teamai packages install crashes in pnpm projects (npm install run in pnpm node_modules tree) #1102

Description

teamai packages install (local / non‑global declarations) always fails in a project that uses pnpm, because the npm adapter shells out to npm install with cwd set to the project root. npm's arborist then tries to read the project's pnpm node_modules layout and crashes:

npm error Cannot read properties of null (reading 'matches')

Root cause chain (npm 11.16.0):

TypeError: Cannot read properties of null (reading 'matches')
    at Link.matches (…/npm/node_modules/@npmcli/arborist/lib/node.js:1183:41)
    at Link.canDedupe (…/lib/node.js:1127:15)
    at PlaceDep.pruneDedupable (…/lib/place-dep.js:426:14)
    at new PlaceDep (…/lib/place-dep.js:278:14)

npm install cannot understand node_modules/.pnpm/** (the symlink farm pnpm creates), so arborist walks a Link whose target is null and dereferences it.

Two problems for a pnpm project:

1. teamai never detects the package manager. grep -c pnpm over teamai-cli@0.27.0/dist/index.js → 0. The npm adapter hardcodes:

   this.execute("npm", ["install", …(global ? ["--global"] : []), …specs, …(registry ? ["--registry", registry] : [])], { cwd: context.cwd })

   There is no packageManager field read, no pnpm/yarn/bun detection, no override knob.
2. Local installs run npm inside the project directory, i.e. exactly the pnpm tree that breaks arborist. (Global installs — --global — do not crash, since they don't parse the project's node_modules.)

Expected: in a pnpm project, teamai packages install should install through pnpm (pnpm add / pnpm add -g), or at minimum not crash and print an actionable message. Issue #325 ("TeamAI 不重造任何包管理器") reserved architecture slots for other ecosystems; pnpm is a package-manager flavor of the npm ecosystem and is currently unsupported.

Reproduction

Minimal, no teamai config needed — the crash is reproducible with a bare npm command in any pnpm project:

# 1. pnpm project with an installed pnpm store
pnpm install

# 2. npm install in that same directory → crash (even --dry-run)
npm install --dry-run lodash
#   npm error Cannot read properties of null (reading 'matches')

Then through teamai (project scope, packages.npm declared or a fresh target):

teamai packages install typescript
#   npm error Cannot read properties of null (reading 'matches')
#   Error: npm install failed (exit 1): npm error Cannot read properties of null …
#     at NpmAdapter.install (…/teamai-cli/dist/index.js:36059:19)
#     at async pkgInstall (…/dist/index.js:36516:7)

Control test proving it is the pnpm layout, not the network or the package:

mkdir /tmp/npmtest && cp package.json /tmp/npmtest/ && cd /tmp/npmtest
npm install --dry-run lodash      # succeeds — no node_modules/.pnpm here
rm -rf /tmp/npmtest

Global path also proves the split:

teamai packages install @playwright/cli --global   # works (no project node_modules walked)

Expected vs actual

• Expected: teamai packages install <pkg> in a pnpm project resolves the dependency graph with pnpm (respecting pnpm-lock.yaml), or exits cleanly with a "pnpm not supported" message.
• Actual: an opaque arborist TypeError surfaced as npm install failed (exit 1), with no hint that the real cause is npm-vs-pnpm layout.

Environment

• OS: Ubuntu 26.04.1 LTS (x64)
• Node.js: v24.18.0
• npm: 11.16.0
• pnpm: 12.10.1
• teamai: 0.27.0
• Provider: CNB (cnb.cool)
• AI tool(s): CodeBuddy

Suggested fixes (any of)

1. Detect the package manager. Read package.json#packageManager / presence of pnpm-lock.yaml / pnpm-workspace.yaml, and route to pnpm add [-g] / yarn add / bun add accordingly. (This is the "扩展位" the Proposal: teamai install — 统一编排 npm 依赖与 Claude 插件市场 #325 design reserved.)
2. Add an explicit override (config key or flag) so a member can force the package manager for a project.
3. Guard the npm path. When a foreign layout is detected (e.g. node_modules/.pnpm exists and the project declares pnpm), skip the npm adapter and warn rather than throw an opaque arborist crash.
4. Nice-to-have: wrap the npm install failure so the error names the likely cause when a pnpm/yarn layout is present.

Logs

npm error Cannot read properties of null (reading 'matches')
npm error A complete log of this run can be found in: /home/bladestone/.npm/_logs/2026-10-13T14_24_16_515Z-debug-0.log
file:///…/teamai-cli/dist/index.js:36059
            throw new Error(`npm install failed (exit ${result.code}): ${result.stderr.trim()}`);
                  ^
Error: npm install failed (exit 1): npm error Cannot read properties of null (reading 'matches')
    at NpmAdapter.install (file:///…/teamai-cli/dist/index.js:36059:19)
    at process.processTicksAndRejections (node:internal/process/task_queues:104:5)
    at async pkgInstall (file:///…/teamai-cli/dist/index.js:36516:7)
    at async run2 (file:///…/teamai-cli/dist/index.js:67881:3)
Node.js v24.18.0

189 verbose stack TypeError: Cannot read properties of null (reading 'matches')
189 verbose stack     at Link.matches (…/@npmcli/arborist/lib/node.js:1183:41)
189 verbose stack     at Link.canDedupe (…/node.js:1127:15)
189 verbose stack     at PlaceDep.pruneDedupable (…/place-dep.js:426:14)
189 verbose stack     at new PlaceDep (…/place-dep.js:278:14)
189 verbose stack     at async Arborist.buildIdealTree (…/build-ideal-tree.js:995:18)
195 verbose cwd /path/to/pnpm-project
198 verbose npm  v11.16.0