fix(pet): fail npm run check when committed native artifacts drift

P01-05 (Refs #6557). The committed native copies of the TypeScript core
(crates/tui/src/tui/pet_watch/pet-native.js, crates/tui/.../shared.html,
pet/ios/Resources/pet-native.js and demo.jsonl, which Android also
packages) were only regenerated by `npm run sync`. `npm run check` never
compared them, so the owned build stayed green beside a stale embedded
core. The CI step `git diff --exit-code` after sync (pet.yml:37) also
omits pet_watch/shared.html, which the owner serves via include_str!.

scripts/build-pet.mjs gains `--check`: it builds dist as before,
regenerates every tracked native output in memory and exits 1 naming each
file whose bytes differ (or which is missing). Without --check the same
list is written, so sync behaviour is unchanged. `npm run check` now runs
the build with --check, and CI already runs `npm --prefix pet run check`.

Validation (pet/):
- npm run check: typecheck ok; "generated native artifacts match";
  ℹ tests 71 / pass 71 / fail 0
- Negative control: appended a comment to public/shared.html ->
  --check exit 1 "stale: ../crates/tui/src/tui/pet_watch/shared.html";
  the previous path (plain build) exit 0 on the same drift. Appended a
  comment to src/core/pet-world.ts -> --check exit 1 naming both
  pet-native.js copies. Both files restored byte-identically (cmp), rerun
  exit 0.

Co-Authored-By: Claude Opus 5.5 <[email protected]>
Signed-off-by: CodeWhale Bot <[email protected]>

pet/README.md

@@ -88,8 +88,8 @@ The Rust particle implementation lives in the product's
 `crates/tui/src/tui/ambient_life/pet_sim.rs`; this package's runner imports it.
 Swift and Kotlin particle ports must match its conformance digests. Generated
 native bundles are committed so the product Rust build needs no Node compiler.
-Run `npm run sync` after changing core source; the generated-byte check in CI
-rejects a stale bundle. Local Whalesong consumers use aliases to these same
+Run `npm run sync` after changing core source; `npm run check` (run by CI)
+rejects a stale bundle or `shared.html` copy. Local Whalesong consumers use aliases to these same
 canonical files, not separately maintained source copies.
 
 The original Whalesong importer, signal model, schema and browser storage code

pet/package.json

@@ -11,7 +11,7 @@
     "build": "node scripts/build-pet.mjs",
     "typecheck": "tsc -p tsconfig.json --noEmit",
     "test": "node --test tests/*.test.mjs",
-    "check": "npm run typecheck && npm run build && npm test",
+    "check": "npm run typecheck && node scripts/build-pet.mjs --check && npm test",
     "start": "python3 -m http.server 4632 --bind 127.0.0.1 --directory dist",
     "sync": "node scripts/build-pet.mjs --tui --apple --study"
   },

pet/scripts/build-pet.mjs

@@ -2,6 +2,7 @@
 /** Local TypeScript build plus deterministic embedded-runtime packaging. */
 import { readFile, writeFile, cp, mkdir } from 'node:fs/promises';
 import { fileURLToPath } from 'node:url';
+import { dirname } from 'node:path';
 import { spawnSync } from 'node:child_process';
 import ts from 'typescript';
 const root = fileURLToPath(new URL('../', import.meta.url));
@@ -23,11 +24,15 @@ const bundle = `/* Generated from pet/src/core. Run npm --prefix pet run sync. *
   + [...modules].map(([id, js]) => `factories[${JSON.stringify(id)}]=function(exports,require){\n${js}\n};\n`).join('')
   + `function load(id){id=id.replace(/^\\.\\//,'').replace(/\\.js$/,'');if(cache[id])return cache[id];if(!factories[id])throw Error('Missing core module');const e=cache[id]={};factories[id](e,load);return e;}\nglobal.PetNative=load('pet-native').PetNative;\n})(globalThis);\n`;
 await writeFile(root + 'dist/pet-native.js', bundle);
-if (process.argv.includes('--tui')) {
+// Committed native copies are generated from src/core and public/. `--check`
+// regenerates them in memory and fails on any byte difference, so a green
+// `npm run check` cannot sit beside a stale embedded TUI/Apple/Android core.
+const check = process.argv.includes('--check');
+const generated = [];
+if (check || process.argv.includes('--tui')) {
   const destination = root + '../crates/tui/src/tui/pet_watch/';
-  await mkdir(destination, { recursive: true });
-  await writeFile(destination + 'pet-native.js', bundle);
-  await cp(root + 'public/shared.html', destination + 'shared.html');
+  generated.push([destination + 'pet-native.js', Buffer.from(bundle)],
+    [destination + 'shared.html', await readFile(root + 'public/shared.html')]);
 }
 if (process.argv.includes('--study')) {
   const study = root + 'world/';
@@ -44,11 +49,23 @@ if (process.argv.includes('--study')) {
     compilerOptions: { target: ts.ScriptTarget.ES2022, module: ts.ModuleKind.ES2022 },
   }).outputText.replace("'./PetSim.ts'", "'./PetSim.js'"));
 }
-if (process.argv.includes('--apple')) {
+if (check || process.argv.includes('--apple')) {
   const { petDemoEvents } = await import('../dist/core/pet-demo.js');
   const { compilePetTelemetry, encodePetJSONL } = await import('../dist/core/pet-telemetry.js');
-  await mkdir(root + 'ios/Resources', { recursive: true });
-  await writeFile(root + 'ios/Resources/pet-native.js', bundle);
-  await writeFile(root + 'ios/Resources/demo.jsonl', encodePetJSONL(compilePetTelemetry(petDemoEvents(), 80_000)));
+  generated.push([root + 'ios/Resources/pet-native.js', Buffer.from(bundle)],
+    [root + 'ios/Resources/demo.jsonl', Buffer.from(encodePetJSONL(compilePetTelemetry(petDemoEvents(), 80_000)))]);
 }
-console.log(`Built pet viewer and native core (${modules.size} shared modules), entirely local.`);
+if (check) {
+  const stale = [];
+  for (const [path, bytes] of generated) {
+    const current = await readFile(path).catch(error => { if (error.code === 'ENOENT') return undefined; throw error; });
+    if (!current || !bytes.equals(current)) stale.push(path.slice(root.length));
+  }
+  if (stale.length) {
+    console.error(`Generated native artifacts are stale: ${stale.join(', ')}. Run npm --prefix pet run sync and commit them.`);
+    process.exit(1);
+  }
+} else {
+  for (const [path, bytes] of generated) { await mkdir(dirname(path), { recursive: true }); await writeFile(path, bytes); }
+}
+console.log(`Built pet viewer and native core (${modules.size} shared modules), entirely local${check ? '; generated native artifacts match' : ''}.`);