feat: interactive JSON / JSON5 mode selector at build time

Lets the operator pick between strict JSON (legacy) and JSON5 for every
configuration file consumed by Nitro and the renderer.

- scripts/configure-json.mjs: interactive prompt (JSON5 recommended),
  with --if-missing and --non-interactive flags for CI use
- package.json: yarn configure / prestart / prebuild hooks
- vite.config.mjs: reads .nitro-build.json (or NITRO_JSON_MODE env) and
  injects the compile-time constant __NITRO_JSON_MODE__ via define
- src/bootstrap.ts: routes client-mode.json parsing through the
  selected mode
- .gitignore: ignore the per-deployment .nitro-build.json
- README: full usage and override section
- public/configuration assets regenerated by the updated prebuild flow

The renderer side (@nitrots/utils JsonParser) is updated in the
companion Nitro_Render_V3 commit on the dev branch.

public/configuration/asset-loader.js

@@ -44,6 +44,11 @@
     return new URL(".", source);
   };
 
+  const getDeployBase = () => {
+    try { return new URL("..", getBase()); }
+    catch { return new URL("/", location.href); }
+  };
+
   const withCacheBust = (url) => {
     url.searchParams.set("v", Date.now().toString(36));
     return url;
@@ -71,9 +76,14 @@
 
   const resolveAssetCandidates = (path) => {
     const base = getBase();
+    const deploy = getDeployBase();
     const normalized = path.replace(/^\.\//, "");
     const file = normalized.split("/").pop();
+    const relative = normalized.replace(/^\//, "");
     const urls = [
+      new URL("src/assets/" + file, deploy),
+      new URL("assets/" + file, deploy),
+      new URL(relative, deploy),
       new URL("./src/assets/" + file, base),
       new URL("./assets/" + file, base),
       new URL("/src/assets/" + file, base.origin),
@@ -205,7 +215,10 @@
 
   const fetchManifest = async () => {
     const base = getBase();
+    const deploy = getDeployBase();
     const candidates = [
+      new URL(".vite/manifest.json", deploy),
+      new URL("manifest.json", deploy),
       new URL(".vite/manifest.json", base.origin + "/"),
       new URL("manifest.json", base.origin + "/"),
       new URL(".vite/manifest.json", base),
@@ -221,7 +234,11 @@
         const json = await response.json();
         if(json && typeof json === "object") {
           debug("loader: manifest from " + candidate.href);
-          return { manifest: json, base: new URL(".", candidate.href) };
+          let manifestBase = new URL(".", candidate.href);
+          if(/\/\.vite\/manifest\.json$/.test(candidate.pathname)) {
+            manifestBase = new URL("..", manifestBase);
+          }
+          return { manifest: json, base: manifestBase };
         }
       } catch {}
     }
@@ -247,18 +264,24 @@
   const resolveManifestPath = (manifestBase, file) => {
     if(/^https?:\/\//i.test(file)) return file;
     if(file.startsWith("/")) return file;
-    return new URL(file, manifestBase.origin + "/").pathname;
+    return new URL(file, manifestBase).pathname;
   };
 
   const isLoaderUrl = (href) => /(?:^|\/)bootstrap\.js(?:$|\?|#)/i.test(href) || /(?:^|\/)asset-loader\.js(?:$|\?|#)/i.test(href);
 
   const fetchEntryFromIndexHtml = async () => {
     const base = getBase();
+    const deploy = getDeployBase();
     const candidates = [
+      new URL("index.html", deploy),
+      new URL("./", deploy),
       new URL("/index.html", base.origin + "/"),
       new URL("/", base.origin + "/")
     ];
+    const seen = new Set();
     for(const candidate of candidates) {
+      if(seen.has(candidate.href)) continue;
+      seen.add(candidate.href);
       try {
         const response = await fetch(withCacheBust(new URL(candidate.href)), { cache: "no-store" });
         if(!response.ok) continue;

public/configuration/bootstrap.js

@@ -1,17 +1,4 @@
 (() => {
-  const API_BASE = "http://localhost:2096";
-
-  const ensureMobileViewport = () => {
-    let viewport = document.querySelector('meta[name="viewport"]');
-    if(!viewport) {
-      viewport = document.createElement("meta");
-      viewport.name = "viewport";
-      document.head.appendChild(viewport);
-    }
-    viewport.content = "width=device-width, initial-scale=1, viewport-fit=cover";
-  };
-
-  ensureMobileViewport();
   const FALLBACK_API_BASE = "";
 
   const getBase = () => {