[Feature]: Python: obj.method() on an annotated parameter or a constructor-bound local produces no calls edge #4197

Problem or use case

affected, explain and shortest_path miss most Python method callers. _resolve_python_member_calls resolves ClassName.method() (#1446) and module.func() (#1883), and #4176 is adding self.attr.method(). A plain local receiver never gets a calls edge, even when the function itself names its class:

from ._models import Request
from ._client import Client

def send(request: Request):       # annotated parameter
    request.read()                 # no edge to Request.read

def build():
    client = Client()              # constructor binding
    client.send()                  # no edge to Client.send

def get(url):
    with Client() as client:       # context manager on a constructor
        return client.get(url)     # no edge to Client.get

Measured against jedi on v8 @ f765dcb (jedi goto on every call inside every function, kept when the target is defined in the repo):

Proposed solution

Type the receiver from the function's own code, only when it is certain: a parameter annotation (X, "X", Optional[X], typing.Optional[X], X | None), x = X(...) / x: X, or with X(...) as x. Any other binding of the name in the function (factory call, loop, unpacking, a second class, lambda parameter, match capture, ...) drops the type. Resolve with the existing class/method index and the same origin gate as the TS receiver arm (#2553): the class name is unique and the class is defined in, imported into, or in a module imported by the caller's file. Otherwise no edge.

Alternatives considered

• Resolve obj.method() by method name alone: rejected, that is the god-node collision the shared pass deliberately skips (Cross-file INFERRED calls resolution lacks import evidence + ambiguous-candidate handling — short common names blow up god_nodes ranking #543/Cross-file calls resolution drops EXTRACTED edges when the callee name has multiple definitions (even with unambiguous import evidence) #1219).
• Return-type inference (x = make_client()): bigger, needs cross-file return types; left out.
• Run jedi/pyright as a resolver: new heavy dependency and not deterministic across environments.

Area

Extraction or language support

Are you willing to submit a PR?

Yes, I can work on this

Compatibility / behavior impact

• Adds INFERRED calls edges only (confidence_score 0.85). No node, id or existing edge changes.
• Raw calls gain receiver_type (the key Ruby already uses), so the AST cache schema goes 5 -> 6 and old warm caches re-extract.
• graph.json schema, generated skills and MCP output formats unchanged. Incremental updates behave the same (warm == cold).

Additional context

PR ready right after this issue. 0.9.79 (f765dcb), Windows 11, Python 3.12.12, built from source.