`& ([scriptblock]::Create((irm ...)))` is the documented Windows install
form. Windows PowerShell 5.1 irm keeps a leading BOM as a literal U+FEFF,
so param( is no longer the first statement and the script dies with "The
assignment expression is not valid". The Windows-lane ParseFile check reads
the BOM as an encoding marker and passes, so nothing caught the BOM that
came back with the MSIX rewrite of install.ps1. This check is
host-independent and runs on the Linux lane.
Red on install.ps1 until its BOM is stripped.
Root-level tests/ is for root-level modules; 19 files testing scripts/, 3 testing
pm/ and 5 testing hermes_cli/ move to the mirrored directory (workflow file lists
and cross-imports updated; path arithmetic bumped one level).
tests/pm gains a conftest with the isolated_machine_home fixture that seven
modules had copy-pasted verbatim.
