fix(installer): preserve fixedRootPackage identity for solver pool

PHP's createRepositorySet does `$this->fixedRootPackage = clone
$this->package;` once and then passes that same object both to `new
RootPackageRepository($this->fixedRootPackage)` and, later, to
createRequest($this->fixedRootPackage) — object identity matters
because the solver assigns a pool id by mutating the package object
itself.

The port instead called RootPackageInterfaceHandle::dup() a second
time when registering the RootPackageRepository, producing a second
object that never went through the pool and so never got an id.
create_request's `request.fix_package(root_package_handle)` then
referenced a package with id -1, which add_rules_for_request treats as
a real bug: "Fixed package ... was not added to solver pool." This
surfaced whenever a create-project run reached the second-stage
install (i.e. every dist-installed project with real dependencies).

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

0 files changed, 0 insertions, 0 deletions