fix(javascript): preserve exact CommonJS export keys

Retain literal property keys as member segments, omit unresolved computed keys, and distinguish nested writes from dotted export names. Preserve empty keys and omit object-literal prototype setters. Verify bundler observations through Node, CLI, and MCP consumers.

src/domain/javascript/javascriptStaticAnalysis.member_path_depth.test.ts

@@ -10,27 +10,41 @@ const ordinaryMemberChain = ".next".repeat(64);
 it("collects a 12,000-member CommonJS export path without recursion", () => {
   const file = parseJavaScriptSource(`exports${memberChain}.last = 1;`);
   if (file === null) throw new Error("Expected valid JavaScript");
-  expect(collectJavaScriptExports(file).values).toEqual([
-    `${"next.".repeat(12_000)}last`,
-  ]);
+  expect(collectJavaScriptExports(file).values).toEqual(["next"]);
 });
 
-it("preserves empty, dynamic, this, and private member path behavior", () => {
+it("preserves exact empty keys without inventing dynamic, this, or private exports", () => {
   const file = parseJavaScriptSource(`
     exports[""].value = 1;
     exports[""] = 0;
     exports[key].value = 2;
+    exports.nested = {};
+    exports.nested.child = 3;
+    exports["nested.child"] = 4;
     this.exports.ignored = 3;
     class Example { #private = 0; read() { this.#private = 1; } }
   `);
   if (file === null) throw new Error("Expected valid JavaScript");
   expect(collectJavaScriptExports(file).values).toEqual([
     "",
-    ".value",
-    "key.value",
+    "nested",
+    "nested.child",
   ]);
 });
 
+it("distinguishes the object literal prototype setter from own export keys", () => {
+  const prototypeSetter = parseJavaScriptSource(
+    "module.exports = { __proto__: {} };",
+  );
+  const ownKeys = parseJavaScriptSource(
+    'module.exports = { ["__proto__"]: 1, __proto__() {} };',
+  );
+  if (prototypeSetter === null || ownKeys === null)
+    throw new Error("Expected valid JavaScript");
+  expect(collectJavaScriptExports(prototypeSetter).values).toEqual([]);
+  expect(collectJavaScriptExports(ownKeys).values).toEqual(["__proto__"]);
+});
+
 it("keeps left-first and outer-member-first bundler runtime matches", () => {
   const source = `
     (globalThis.webpackChunkLeft || globalThis.webpackChunkRight).push([[1], { 1: function() {} }]);