Add checked query composition foundations for prepared presentations

Move React navigation query generation behind an explicit build frontend. Add checked result-dependent query bindings and pure composition evaluation, including one-snapshot server execution. Preserve the existing rendering path while the React manifest, worker preparation, and replica admission integration remain pending; see docs/PREPARED_PRESENTATIONS_PROGRESS.md.

src/capability-language/component-scaffold.ts

@@ -55,12 +55,17 @@ export async function scaffoldComponent(
   const insertion = `  ${nixLiteral(spec.id)} = { entry = ${nixLiteral(`src/components/${spec.name}.tsx`)}; export = ${nixLiteral(spec.name)}; };\n`;
   const after = before.replace(/\n}(\s*)$/, (_match, trailing) => "\n" + insertion + "}" + trailing);
   const parentID = parent.children.find((node) => node.kind === "stringLiteral")!;
+  const configFile = prefix + "quixos.check.json";
+  const configBefore = await fs.readFile(path.join(root, configFile), "utf8");
+  const config = JSON.parse(configBefore);
+  config.queryFrontends = [...new Set([...(config.queryFrontends ?? []), "react"])];
   return {
     kind: "package",
     source: spec.source,
     resourceRoot: spec.directory,
     validation: "syntax",
     files: [
+      { file: configFile, expected: configBefore, replace: JSON.stringify(config, null, 2) + "\n" },
       {
         file: prefix + "package.qx",
         edits: [