fix(javascript)!: preserve property paths and uncertain slot presence

Use one explicit object/array slot model and JSON-pointer property identity across mutation analysis, return projection, and semantic graphs. Require observed presence for discriminants and resolve writes only through retained object or array receivers.

BREAKING CHANGE: projected return fields require explicit presence and semantic object operations carry full property paths.

src/domain/javascript/javascriptSemanticAnalysis.member_depth.test.ts

@@ -62,7 +62,11 @@ it("invalidates a deep mutation while retaining unrelated literal properties", (
   expect(onlyBinding(ir, "root").value).toEqual({
     status: "object",
     properties: [
-      { name: "untouched", value: { status: "literal", value: "retained" } },
+      {
+        name: "untouched",
+        presence: "present",
+        value: { status: "literal", value: "retained" },
+      },
       {
         name: "next",
         presence: "unknown-coverage",