feat: add proxyVarSubDir option to path extenders

[zkochan]

Summary

• Add proxyVarSubDir option to posix, windows, and main path extender interfaces
• When set, the PATH entry uses a subdirectory of the proxy variable (e.g. $PNPM_HOME/bin instead of $PNPM_HOME)
• Supports all shell types: bash/zsh (case statement), fish, nushell, and Windows registry
• Validate proxyVarSubDir to reject unsafe values (leading slashes, .., shell metacharacters)
• Remove pnpm.builder/policy component (scope has been removed from Bit)
• Add @teambit/builder as explicit workspace dependency
• Update CI Node.js matrix to 22 and 24

Test plan

• Added bash/zsh test for proxyVarSubDir
• Added fish test for proxyVarSubDir
• Added nushell test for proxyVarSubDir
• Verify existing tests still pass
• Test on Windows with the new proxyVarSubDir option

🤖 Generated with Claude Code

[Copilot]

Pull request overview

This PR extends the PATH manipulation utilities to support adding a subdirectory of a proxy environment variable (e.g. $PNPM_HOME/bin / %PNPM_HOME%\bin) across POSIX shells and Windows, and wires the option through the shared addDirToEnvPath entrypoint.

Changes:

• Add a new proxyVarSubDir option to POSIX + Windows path extender option types and implementations.
• Update POSIX shell rendering (bash/zsh/ksh/sh, fish, nushell) and Windows registry PATH entry construction to use the proxy var subdirectory when set.
• Update tests for POSIX bash path extender output with proxyVarSubDir: 'bin'.

Reviewed changes

Copilot reviewed 12 out of 14 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
os/env/path-extender/path-extender.ts	Passes the new proxyVarSubDir option through to the Windows implementation.
os/env/path-extender-posix/path-extender-posix.ts	Adds proxyVarSubDir and uses it when generating PATH updates for sh-compatible shells, fish, and nushell.
os/env/path-extender-windows/path-extender-windows.ts	Adds proxyVarSubDir and builds a %VAR%\subdir PATH entry when set.
os/env/path-extender-posix/path-extender-posix.spec.ts	Adds a bash coverage test for the new $PNPM_HOME/bin behavior.
.github/workflows/ci.yml	Changes CI Node.js matrix to only 22 and 24.
.bitmap + builder/policy/* deletions	Removes the builder/policy Bit component from the workspace.
pnpm-lock.yaml	Large lockfile rewrite, including new deprecation notices (e.g. basic-ftp@5.0.5, puppeteer@24.3.0).
.gitignore	Adds .claude to ignored files.

Comments suppressed due to low confidence (1)

os/env/path-extender-posix/path-extender-posix.ts:24

• The public options interface now includes proxyVarSubDir, but the package docs/examples (e.g. path-extender-posix.docs.mdx / path-extender-windows.docs.mdx) don’t describe this new option or its effect on PATH entries. Please update the documentation to include the new option and an example (like $PNPM_HOME/bin).

export interface AddDirToPosixEnvPathOpts {
  proxyVarName?: string
  proxyVarSubDir?: string
  overwrite?: boolean
  position?: AddingPosition
  configSectionName: string
}

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[Copilot]

New Windows behavior (proxyVarSubDir) is introduced here but isn't covered by path-extender-windows.spec.ts. Please add a unit test asserting the Path entry becomes something like %PNPM_HOME%\\bin when proxyVarSubDir: 'bin' is provided, including both prepend/append positions.

[zkochan]

Windows path extender tests require registry access and can only run on Windows. Skipping for now.

[zkochan]

Added Windows test for proxyVarSubDir.