Instrument and improve incremental workspace checks

Profile source capture, Nix evaluation/realization, resource/query checking,
and implementation builds without putting timings into immutable outputs.
Keep modular repositories; bound independent capture work, snapshot jj once
per observation, and retain final concurrent-edit and Git completeness checks.

Compose exact resource/closure/frontend/toolchain checks as memoized Nix
derivations. Preserve whole-workspace validation and the full compiler path
when no checked dependency is supplied. Share canonical Nixpkgs by content,
index workspace build contexts once, and narrow lock/driver/compiler inputs
with conservative complete-source fallback. Batch React witness checks only
when distinct source closures cannot share ambient declarations; otherwise
run the original independent TypeScript checks.

Seed local authoring toolchains with exact canonical fetch identities when
they match the selected inputs; retain store-path inputs for overrides.
Add generic correctness checks rather than permanent Reader timing/content
fixtures. Verify actual Reader edits and rejection/recovery in a private
workbench, preserving the original user's workbench and runtime.

Query checking currently caches at resource/closure boundaries, not individual
query semantic dependency boundaries. Template helper pins and reproducible
fixture snapshots follow in a separate publication change.

component-types.test.mjs

@@ -0,0 +1,59 @@
+import assert from "node:assert/strict";
+import { mkdtemp, writeFile, rm } from "node:fs/promises";
+import os from "node:os";
+import path from "node:path";
+import test from "node:test";
+import { checkComponentTypes } from "./component-types.mjs";
+
+const tsc = process.env.QUIXOS_TYPESCRIPT;
+if (!tsc) throw Error("Pass the selected TypeScript compiler path");
+async function fixture(context, left, right) {
+  const work = await mkdtemp(path.join(os.tmpdir(), "component-types-"));
+  context.after(() => rm(work, { recursive: true, force: true }));
+  await Promise.all(
+    Object.entries({ "left.ts": left, "right.ts": right, "assets.d.ts": "", "props.d.ts": "" }).map(([file, source]) =>
+      writeFile(path.join(work, file), source),
+    ),
+  );
+  return {
+    node: process.execPath,
+    tsc,
+    work,
+    witnesses: ["left.ts", "right.ts"],
+    assets: "assets.d.ts",
+    props: "props.d.ts",
+    packageRevision: "test",
+  };
+}
+test("shared component typechecking accepts all valid witnesses", async (context) => {
+  checkComponentTypes(await fixture(context, "export const left: string = 'ok';", "export const right: number = 1;"));
+});
+test("independently valid ambient declarations use the full individual check fallback", async (context) => {
+  checkComponentTypes(
+    await fixture(
+      context,
+      "export {}; declare global { interface Application { value: string; } }",
+      "export {}; declare global { interface Application { value: number; } }",
+    ),
+  );
+});
+test("a type error in any witness still rejects the artifact", async (context) => {
+  const input = await fixture(context, "export const left: string = 'ok';", "export const right: string = 1;");
+  assert.throws(() => checkComponentTypes(input));
+});
+test("one witness's globals cannot make an independently invalid witness pass", async (context) => {
+  const input = await fixture(
+    context,
+    "export {}; declare global { interface Application { value: string; } }",
+    "export const right: Application = {value: 'ok'};",
+  );
+  assert.throws(() => checkComponentTypes(input));
+});
+test("an ambient module from another source closure cannot resolve a missing import", async (context) => {
+  const input = await fixture(
+    context,
+    "declare module 'missing-component-package' { export const value: string; }",
+    "import {value} from 'missing-component-package'; export const right = value;",
+  );
+  assert.throws(() => checkComponentTypes(input));
+});