test(extract): cover builtin static-call shape (Date.now()) for #1726

Adds a regression test for the Date.now()/static-call shape (credit PR #1727 /
@2loch-ness6, who independently found the same fix): a capitalized builtin
receiver must not bind cross-file to a same-spelled user const/class. The same
guard added in 67f4f83 already covers it (verified); this locks the static-call
shape in, while allowing the legitimate same-file const reference.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

tests/test_builtin_global_type_refs.py

@@ -50,3 +50,34 @@ def test_nonbuiltin_receiver_type_still_resolves(tmp_path):
     }
     assert any(t and "charge" in str(t).lower() for _, t, _ in resolved), \
         f"user member-call must still resolve; got {resolved}"
+
+
+def test_builtin_static_call_does_not_bind_to_user_symbol(tmp_path):
+    # #1726 (static-call shape, credit PR #1727 / @2loch-ness6): `Date.now()` treats
+    # the capitalized receiver `Date` as a type name; without the builtin guard it
+    # binds to a same-spelled user `const DATE`, a false god node. A typed param in
+    # the same class arms the cross-file member-call resolver (the real service shape).
+    (tmp_path / "format.ts").write_text(
+        "const DATE = new Intl.DateTimeFormat('en-US', {});\n"
+        "export function fmt(x: number): string { return DATE.format(x); }\n")
+    (tmp_path / "svc.ts").write_text(
+        "export class Svc {\n"
+        "  expiry(d: Date): Date { return d; }\n"
+        "  stamp(): number { return Date.now(); }\n"
+        "  when(): string { return new Date().toISOString(); }\n"
+        "}\n")
+    r = extract(sorted(tmp_path.glob("*.ts")), cache_root=tmp_path, parallel=False)
+    lbl = _labels_by_id(r)
+    by_id = {n["id"]: n for n in r["nodes"]}
+    date_ids = [n["id"] for n in r["nodes"] if n.get("label") == "DATE"]
+    date_sf = {str(by_id[i].get("source_file", "")) for i in date_ids}
+    # A same-file reference to the real const DATE (fmt() -> DATE in format.ts) is
+    # legitimate. The bug is a CROSS-FILE bind: svc.ts's Date.now()/new Date()
+    # resolving to format.ts's const DATE. Assert no such cross-file phantom.
+    for e in r["edges"]:
+        if e.get("target") in date_ids and e.get("relation") == "references":
+            src_sf = str(by_id.get(e["source"], {}).get("source_file", ""))
+            assert src_sf in date_sf, (
+                f"cross-file builtin phantom: {lbl.get(e['source'])!r} in {src_sf} "
+                f"bound to user DATE"
+            )