fix(extraction): land upstream declaration initializer walks (#1511) (#1802)

Squash danusha2345's PR #1511 at d282f9e8 onto main 8c9c4761,
preserving its nine non-merge commits and main's existing Unreleased notes.
Calls in Kotlin, Java, TS/JS, Scala, Rust and Python declaration initializers
now retain the owner established by the upstream regression expectations.
Include the upstream CFML, dynamic-dispatch summary and viewer follow-ups.

Linux fail-to-pass validation (Node 22.19.0, rebuilt dist and native kernel):
- Before: TS load belonged to file:app.ts; Python/Kotlin/Scala/Rust calls
  vanished; Java lost the field-lambda, anonymous override and eager calls.
- After: all six languages PASS; 12 native/WASM LF/CRLF parity checks PASS.
- Focused initializer regressions: 10 passed with CODEGRAPH_KERNEL=0 and
  10 passed with the kernel enabled; Kotlin's grammar fallback is recorded.
- Related regression suites: 879 passed, 1 skipped across 15 test files.
- Evidence: /workspace/cg-1510-repro/before and /workspace/cg-1510-repro/after
  (combined test output: after/vitest.log).

Fixes #1510
Supersedes #1511

Co-authored-by: Colby McHenry <colbymchenry@users.noreply.github.com>
Co-authored-by: danusha2345 <ewidusoc498@gmail.com>

codegraph-kernel/src/python.rs

@@ -475,14 +475,37 @@ impl<'t> Walker<'t> {
         let docstring = preceding_docstring(node, self.src);
         let left = node.child_by_field_name("left").or_else(|| node.named_child(0));
         let right = node.child_by_field_name("right").or_else(|| node.named_child(1));
-        let Some(left) = left else { return };
-        if !matches!(left.kind(), "identifier" | "constant") {
-            return;
+        let mut assigned: Option<(u32, String)> = None;
+        if let Some(left) = left {
+            if matches!(left.kind(), "identifier" | "constant") {
+                let name = self.text(left).to_string();
+                let signature = right.map(|r| util::init_signature(self.text(r)));
+                // No isConst hook ⇒ always `variable` (UPPER_CASE constants included).
+                let row = self.create_node(
+                    "variable",
+                    &name,
+                    node,
+                    Extra { docstring, signature, ..Extra::default() },
+                );
+                if let Some(row) = row {
+                    assigned = Some((row, name));
+                }
+            }
+        }
+        // Walk the initializer ATTRIBUTED to the assigned name (#693): a
+        // module-level `app = FastAPI()` / `handler = lambda: run()` dropped
+        // every call on the right-hand side. A tuple target mints no symbol, so
+        // its RHS is walked at the enclosing scope rather than lost.
+        if let Some(right) = right {
+            match assigned {
+                Some((row, name)) => {
+                    self.stack.push(Scope { row, kind: "variable", name });
+                    self.visit_function_body(right);
+                    self.stack.pop();
+                }
+                None => self.visit_function_body(right),
+            }
         }
-        let name = self.text(left).to_string();
-        let signature = right.map(|r| util::init_signature(self.text(r)));
-        // No isConst hook ⇒ always `variable` (UPPER_CASE constants included).
-        self.create_node("variable", &name, node, Extra { docstring, signature, ..Extra::default() });
     }
 
     fn extract_import(&mut self, node: Node<'t>) {