… Item.from_parent

The _check_item_and_collector_diamond_inheritance validation is not
data storage — it's a one-time class-level check. Moving it to
from_parent keeps __init__ focused on storing values.

Also converts the method to a classmethod since it only inspects
the class, not the instance.

Co-authored-by: Cursor AI <ai@cursor.sh>
Co-authored-by: Anthropic Claude <claude@anthropic.com>

…m_parent

Package.__init__ only did `session = parent.session` which FSCollector
already handles. Removing the __init__ entirely and adding an explicit
from_parent with a typed signature for clarity.

Also removes the now-unused LEGACY_PATH import from python.py.

Co-authored-by: Cursor AI <ai@cursor.sh>
Co-authored-by: Anthropic Claude <claude@anthropic.com>

…smethods and from_parent

Extracts _derive_name and _derive_nodeid as classmethods on FSCollector.
The from_parent method now pre-computes name and nodeid before calling
super, so __init__ receives fully resolved values in the normal path.

The __init__ retains fallback derivation for backward compatibility
with non-cooperative constructors (plugins using positional args).

Co-authored-by: Cursor AI <ai@cursor.sh>
Co-authored-by: Anthropic Claude <claude@anthropic.com>

…to from_parent

DoctestItem.__init__ now only stores runner, dtest, and obj. The
fixture resolution (getfixtureinfo) and _initrequest() are moved to
from_parent, which is the only production entry point for creating
DoctestItem instances.

Co-authored-by: Cursor AI <ai@cursor.sh>
Co-authored-by: Anthropic Claude <claude@anthropic.com>

…nit__ to from_parent

Function.__init__ now only stores _obj, _instance, originalname, and
callspec. The marker extension, keyword updates, fixture resolution
(getfixtureinfo), and _initrequest() are extracted into a new
_setup_markers_and_fixtures method called from from_parent after
construction.

This keeps __init__ focused on storing values while from_parent
handles all post-construction initialization logic.

Co-authored-by: Cursor AI <ai@cursor.sh>
Co-authored-by: Anthropic Claude <claude@anthropic.com>

1. FSCollector: fix double _imply_path call that would produce duplicate
   deprecation warnings when fspath is used. Now __init__ skips the
   _imply_path call when path is already resolved (by from_parent),
   using _check_path for consistency validation instead.

2. Function: remove dead keywords/fixtureinfo parameters from __init__
   since from_parent now pops them before calling super. Replace with
   **kw for forward-compatibility with additional kwargs.

Co-authored-by: Cursor AI <ai@cursor.sh>
Co-authored-by: Anthropic Claude <claude@anthropic.com>