feedback5: the public dev branch is marked as a development build (the owner's decision of 2026-10-06): version 0.2.0-dev (title footer, boot banner, /healthz), a README warning under the title (unstable, not for public servers, how to report, shared browser storage, no release zips), a visible 开发版 tag on the title screen (zh / en), a boot-banner warning for hosts, and tools/package.mjs refuses a dev version without --allow-dev; test/version.test.js checks all of it

public/css/screens/title.css

@@ -261,3 +261,13 @@ html[data-lang="en"] .title-login .btn--xl { letter-spacing: .3em; }
   font-size: .13rem;
   color: var(--text-dim);
 }
+/* a development build (shared/constants.js DEV_BUILD): an unmissable tag in the footer */
+.title-dev {
+  padding: .03rem .1rem;
+  border: 1px solid #ff9f43;
+  border-radius: .04rem;
+  color: #ffb066;
+  background: rgba(255, 159, 67, .14);
+  font-weight: 700;
+  letter-spacing: .02em;
+}

public/i18n/en.json

@@ -1014,5 +1014,6 @@
   "还有 {funds} 资金未使用。休整期结束时，本回合的剩余资金将清零。确定准备就绪吗？": "You still have {funds} unspent Funds. The round's leftover Funds are cleared when the Rest Phase ends. Ready anyway?",
   "选择「{name}」的朝向": "Choose {name}'s facing",
   "选择朝向": "Choose a facing",
-  "朝向：{dir}": "Facing: {dir}"
+  "朝向：{dir}": "Facing: {dir}",
+  "开发版 · 不稳定，请勿用于公开服务器": "Development build · unstable, not for public servers"
 }

public/js/screens/title.js

@@ -10,7 +10,7 @@
 // pure CSS/SVG (radar, ridgelines, glow), so it never issues a request that can 404.
 
 import { useMemo, useState } from '../../vendor/hooks.module.js';
-import { NAME_MAX_LEN, APP_VERSION } from '../../../shared/constants.js';
+import { NAME_MAX_LEN, APP_VERSION, DEV_BUILD } from '../../../shared/constants.js';
 import { html, Button, Icon, MicroLabel, TextField, PingPill } from '../ui/components.js';
 import { GuideButton } from '../ui/guide.js';
 import { toast } from '../ui/toasts.js';
@@ -280,6 +280,7 @@ export function TitleScreen() {
     <footer class="title-foot">
       <span>${t('非官方同人复刻 · 游戏素材版权归 上海鹰角网络 / Yostar 所有')}</span>
       <${MicroLabel}>v${APP_VERSION} · WEB SIMULATION<//>
+      ${DEV_BUILD ? html`<span class="title-dev" role="note">${t('开发版 · 不稳定，请勿用于公开服务器')}</span>` : null}
     </footer>
   </div>`;
 }