fix(extraction): record instantiates for C++ stack/brace construction (#1035) (#1049)

`instantiates` edges came only from heap `new Calculator(0)` (a
new_expression) and copy-init `Calculator c = Calculator(0)` (a
call_expression). Stack direct-init `Calculator calc(0)` and brace-init
`Widget w{1, 2}` parse as a `declaration` whose constructor arguments hang
directly off the declarator as an argument_list / initializer_list — there
is no call/new node — so the function-body walker saw no constructor
invocation and emitted no edge. A function that built objects with the
ordinary stack syntax looked like it didn't construct them, and the
dependency was missing from impact / callers.

In the body walker, a C++ `declaration` that is a stack/brace construction
now reuses extractInstantiation (a declaration's `type` field IS the
constructed class name, and extractInstantiation already strips template
args / namespace and emits the `instantiates` ref). Gated by
isCppStackConstruction, which requires BOTH a class-like type
(type_identifier / template_type / qualified_identifier — so `int x(0)`
and `auto z = …` are excluded) AND a declarator carrying args
(argument_list / initializer_list — so default `Calculator c;` and the
most-vexing-parse `Calculator c();` are excluded). The edge targets the
class node, not the same-named constructor method.

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

CHANGELOG.md

@@ -15,6 +15,7 @@ and adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 - CodeGraph no longer shows a misleading "different git working tree" warning when you work inside a submodule (or other nested repo) of a workspace you indexed at its root. Because indexing a workspace now pulls in its submodules and embedded clones, a query run from inside one correctly resolves up to the workspace's single index — but it was still warning that the results came from "a different working tree" and suggesting you run `codegraph init -i`, which would have split the submodule back out into its own separate index and undone the unified view. CodeGraph now recognizes that the nested repo's code is already part of the workspace index and stays quiet. The warning still appears for a genuine git worktree — a second checkout of the *same* repository on another branch, which really does have its own uncommitted symbols — since that's the case it exists for. (#1031, #1033)
 - On Windows, CodeGraph's background server now shuts down cleanly instead of occasionally aborting with a crash error. When the indexed project contained a nested repository (a submodule or embedded clone), stopping the server could race the file watcher's teardown and exit with a Windows crash code rather than a clean exit. Shutdown now lets that teardown finish first, so the server stops cleanly and promptly. (Windows only; other platforms were unaffected.) (#1033)
 - C++ classes that inherit from a templated base — `class Widget : public Base<int>`, a CRTP base like `class App : public CRTPBase<App>`, or a struct inheriting a template — are now linked to that base class in the graph. Previously the template arguments (`<int>`) made the inheritance go unrecognized, so these classes looked like they inherited from nothing and impact/callers analysis stopped at the boundary; the connection is now followed like any other base class. Thanks @ryancu7 for the report. (#1043)
+- C++ objects constructed on the stack — `Calculator calc(0)` or `Widget w{1, 2}` — now record that the enclosing function instantiates that class, the same as heap construction (`new Calculator(0)`) already did. Previously only the `new` form was tracked, so a function that built objects with the ordinary stack syntax looked like it didn't construct them and the dependency was missing from impact/callers. Thanks @Dshuishui for the report. (#1035)
 
 
 ## [1.1.2] - 2026-06-28