perf(web): skip unchanged incremental web builds

tools/web/incremental-web-build.mjs

@@ -0,0 +1,23 @@
+import { spawnSync } from "node:child_process";
+import fs from "node:fs";
+import { fingerprint, readState, root, writeState } from "./web-build-fingerprint.mjs";
+
+const currentFingerprint = fingerprint();
+const state = readState("web-build-success.json");
+const index = `${root}/web/dist/index.html`;
+if (state?.fingerprint === currentFingerprint && fs.existsSync(index)) {
+  process.stdout.write(`web-build-reused fingerprint=${currentFingerprint}\n`);
+  process.exit(0);
+}
+
+const typecheck = spawnSync(process.execPath, ["tools/web/run-incremental-typecheck.mjs"], {
+  cwd: root,
+  stdio: "inherit",
+});
+if (typecheck.status !== 0) process.exit(typecheck.status ?? 1);
+const vite = spawnSync(process.execPath, ["./node_modules/vite/bin/vite.js", "build", "--config", "app/vite.config.ts"], {
+  cwd: `${root}/web`,
+  stdio: "inherit",
+});
+if (vite.status !== 0) process.exit(vite.status ?? 1);
+writeState("web-build-success.json", { schemaVersion: 1, fingerprint: currentFingerprint });