fix: prepend PowerShell call operator when activating environments

[d-biehl]

Fixes #196.

Problem

Activating a Hatch environment in a PowerShell terminal fails with a ParserError when the Hatch executable path contains a space (e.g. the standalone installer's C:\Program Files\Hatch\hatch.EXE). The host quotes the executable, and PowerShell parses a leading quoted string as an expression rather than a command to run:

"C:\Program Files\Hatch\hatch.EXE" --env=devel.py3.14-rf74 shell
ParserError: Unexpected token 'env=devel.py3.14-rf74' in expression or statement.

Invoking a quoted executable in PowerShell requires the call operator &. The ms-python.vscode-python-envs host adds it automatically on its run path (runInTerminal.ts) but not on the activation path (getShellCommandAsString), so the manager has to supply it for PowerShell — which the built-in venv/poetry managers do, but this manager did not.

Fix

Add a pwsh-specific shellActivation entry that prefixes the call operator, matching the built-in managers ({ executable: '&', args: [...] }). A lone & is left unquoted by the host's quoting, producing:

& "C:\Program Files\Hatch\hatch.EXE" --env devel.py3.14-rf74 shell

'pwsh' covers both Windows PowerShell 5.x and PowerShell 7; cmd/bash/zsh/fish keep using the shared 'unknown' entry, where & is neither needed nor valid. The --env flag and its value are now passed as separate args so only the value is quoted when needed.

Testing

Verified manually on Windows with PowerShell — activation now works. tsc --noEmit and biome check pass.

[flying-sheep]

thanks!