Keep the chrome lazy for error pages, guard the guard-error render, split the recovery link

AGENTS.md

@@ -127,6 +127,11 @@ them. Revisit only if the stated reason stops holding.
   so a localized list page doesn't hand a plugin a phantom `locale` filter; the i18n view locals (`t`, `locale`, `locales`, `localeHref`,
   `localeParam`, `localeSwitch`, `dir`) are likewise reserved names, merged after a handler's `data`
   so a collision loses the key instead of breaking the shell.
+- **The language picker never appears on a POST-rendered page.** That URL frequently answers no GET
+  (`POST /admin/users/:id/recovery` renders a page and has no GET sibling), so a link there dead-ends
+  on a 405; on a re-rendered form it would also discard the visitor's input. `i18nLocals` returns an
+  empty `localeSwitch` for any non-GET/HEAD method, and the picker renders nothing below two choices.
+  Decided 2026-08-03 after a review reproduced the 405.
 - **A plugin-owned render always runs on that plugin's context.** The landing slots (`home`,
   `dashboard`) and an `onRequest` short-circuit dispatch a plugin's handler, so they build the
   context with `contextFor(pluginId)` exactly as a plugin route does — otherwise `ctx.t` is the core

README.md

@@ -940,7 +940,10 @@ is stored, so a link is shareable and a page is what its address says it is. Whe
 for a language, the host carries `?locale=` onto every link *it* renders (menu, sign-in, its own
 redirects) and `ctx.localeHref(href)` does the same for a plugin's links. The picker in the
 sidebar footer (and on the auth pages) lists every installed locale, each a plain link to the
-same page in that language — it renders only when more than one is installed.
+same page in that language. It renders only when more than one is installed, and **not at all on a
+page rendered in response to a POST** — that URL often answers no GET (following the link would
+dead-end), and on a re-rendered form it would throw away what the visitor typed. A plugin building
+its own picker from `ctx.locales` should do the same (`ctx.req.method`).
 
 **Writing a catalog.** `en-US.ts` exports the object and its type; every other locale is written
 against that type, so a missing or misspelled key is a type error before the app ever boots:

e2e-tests/full-flow.spec.ts

@@ -88,6 +88,7 @@ test.describe.serial("authenticated admin journey", () => {
     const row = page.locator("tr", { hasText: `lang-${suffix}@plainpages.local` });
     const editHref = await row.locator('a[href^="/admin/users/"]').first().getAttribute("href");
     await page.goto(`${editHref}`);
+    await expect(page.locator('summary[aria-label="Språk"]')).toHaveCount(1); // control: it IS there on the GET
     await page.getByRole("button", { name: "Skapa återställningskod" }).click(); // POST-only route
     await expect(page.getByText("Återställningskod skapad")).toBeVisible();
     await expect(page.locator('summary[aria-label="Språk"]')).toHaveCount(0); // no dead-end link offered

examples/plugins/admin/i18n/en-US.ts

@@ -138,8 +138,8 @@ const messages = {
   "admin.users.new": "New user",
   "admin.users.pagination": "Users pagination",
   "admin.users.reactivate": "Reactivate",
-  "admin.users.recovery.body":
-    "Give it to the user — they enter it on the <a href=\"/recovery\">password-reset screen</a> to set a new password (generate a fresh one if it has expired).",
+  "admin.users.recovery.body": "Give it to the user — they enter it to set a new password (generate a fresh one if it has expired):",
+  "admin.users.recovery.link": "the password-reset screen",
   "admin.users.recovery.generate": "Generate recovery code",
   "admin.users.recovery.title": "Recovery code generated",
   "admin.users.save": "Save changes",

examples/plugins/admin/i18n/sv-SE.ts

@@ -138,8 +138,8 @@ const messages: AdminMessages = {
   "admin.users.new": "Ny användare",
   "admin.users.pagination": "Sidnavigering för användare",
   "admin.users.reactivate": "Aktivera igen",
-  "admin.users.recovery.body":
-    "Ge den till användaren — koden anges på <a href=\"/recovery\">sidan för lösenordsåterställning</a> för att sätta ett nytt lösenord (skapa en ny om den hunnit gå ut).",
+  "admin.users.recovery.body": "Ge den till användaren — koden anges för att sätta ett nytt lösenord (skapa en ny om den hunnit gå ut):",
+  "admin.users.recovery.link": "sidan för lösenordsåterställning",
   "admin.users.recovery.generate": "Skapa återställningskod",
   "admin.users.recovery.title": "Återställningskod skapad",
   "admin.users.save": "Spara ändringar",

examples/plugins/admin/views/partials/user-form-body.ejs

@@ -14,7 +14,7 @@
 <%- include("partials/alert", { text: locals.error, tone: "neg" }) %>
 <% } -%>
 <% if (recovery) { -%>
-  <div class="alert alert-pos" role="status"><svg class="ico ico-sm" aria-hidden="true"><use href="#i-check-circle"/></svg><div class="alert-body"><strong><%= t("admin.users.recovery.title") %></strong><span><%- t("admin.users.recovery.body") %></span><% if (recovery.code) { %><span class="recovery-code"><code><%= recovery.code %></code></span><% } %></div></div>
+  <div class="alert alert-pos" role="status"><svg class="ico ico-sm" aria-hidden="true"><use href="#i-check-circle"/></svg><div class="alert-body"><strong><%= t("admin.users.recovery.title") %></strong><span><%= t("admin.users.recovery.body") %> <a href="<%= localeHref("/recovery") %>"><%= t("admin.users.recovery.link") %></a></span><% if (recovery.code) { %><span class="recovery-code"><code><%= recovery.code %></code></span><% } %></div></div>
 <% } -%>
   <form class="form-card" method="post" action="<%= localeHref(form.action) %>">
     <input type="hidden" name="_csrf" value="<%= form.csrfToken %>">

src/http/app.test.ts

@@ -23,6 +23,7 @@ import type { Plugin } from "../plugin-host/plugin.ts";
 import { contentTypeFor, resolveStaticPath, routePublic } from "./static.ts";
 import adminManifest from "../../examples/plugins/admin/plugin.ts";
 import { createI18n } from "../i18n/runtime.ts";
+import type { MenuConfig } from "../ui/menu-config.ts";
 import { loadI18n } from "../i18n/load.ts";
 
 const viewsDir = join(dirname(fileURLToPath(import.meta.url)), "..", "..", "views");
@@ -1486,3 +1487,19 @@ test("a plugin that owns a landing page, or short-circuits a hook, translates fr
   assert.equal(await (await fetch(`${url}/hooked`)).text(), "Hello from the plugin");
   assert.equal(await (await fetch(`${url}/dashboard`, { headers: { cookie } })).text(), "Hello from the plugin");
 });
+
+test("an error page renders without composing the menu — it exists for when the shell's data is what failed", async (t) => {
+  // The chrome getter is lazy on purpose; a render that reads no chrome must not trigger it, or a
+  // broken menu takes the error pages down with it.
+  let built = 0;
+  const menu: MenuConfig = { branding: { get name() { built++; return "Plainpages"; } }, override: {} };
+  const app = createApp({ jwks: staticJwks([ecJwk]), menu });
+  await new Promise<void>((r) => app.listen(0, r));
+  t.after(() => app.close());
+  const url = `http://localhost:${(app.address() as AddressInfo).port}`;
+
+  const res = await fetch(`${url}/no-such-page`);
+  assert.equal(res.status, 404);
+  assert.match(await res.text(), /Page not found/);
+  assert.equal(built, 0);
+});

src/http/app.ts

@@ -120,7 +120,17 @@ export function createApp(options: AppOptions = {}): Server {
   // it. A plugin's context carries that plugin's translator, so its own catalog wins in its own views.
   // They are merged LAST: these names are reserved (README → Building plugins), and a handler that
   // happens to use one loses that key rather than breaking the shell that renders around it.
-  const localsOf = (ctx: RequestContext): I18nRequest => ({ ...ctx, method: ctx.req.method ?? "GET" });
+  // Named field by field on purpose: spreading the context would trigger its lazy `chrome` getter,
+  // composing the menu for every render — including the standalone error pages, which exist to
+  // render when the shell's own data is what failed.
+  const localsOf = (ctx: RequestContext): I18nRequest => ({
+    locale: ctx.locale,
+    localeHref: ctx.localeHref,
+    locales: ctx.locales,
+    method: ctx.req.method ?? "GET",
+    t: ctx.t,
+    url: ctx.url,
+  });
   const viewsFor = (ctx: RequestContext): ViewRenderer => (view, data) => render(view, { ...data, ...i18nLocals(localsOf(ctx)) });
   const pluginViewsFor = (ctx: RequestContext, id: string): ViewRenderer => (view, data) => renderView(id, view, { ...data, ...i18nLocals(localsOf(ctx)) });
 
@@ -307,7 +317,9 @@ export function createApp(options: AppOptions = {}): Server {
         }
         csrfMint.setCookie();
         const result = (await match.route.handler(routeCtx)) ?? null;
-        if (anyResponseHooks) await runResponseHooks(plugins, contextFor, result); // observers; a throw → 500
+        // The responding plugin observes its own route, params and all; the others get a plain
+        // context for their own id (never another plugin's params).
+        if (anyResponseHooks) await runResponseHooks(plugins, (id) => (id === match.plugin.id ? routeCtx : contextFor(id)), result);
         await sendResult(res, result, pluginViewsFor(routeCtx, match.plugin.id), carryLocale);
         return;
       }
@@ -334,7 +346,14 @@ export function createApp(options: AppOptions = {}): Server {
       if (err instanceof GuardError) {
         if (res.headersSent) return void res.end();
         if (err.location) return void res.writeHead(303, { location: err.location }).end();
-        return void sendHtml(res, err.status, await renderPage("403", {}));
+        try {
+          return void sendHtml(res, err.status, await renderPage("403", {}));
+        } catch (renderErr) {
+          // Same last resort as the 500 branch below: a throw here would leave the socket open
+          // (this catch is the one that would have handled it), so end the response ourselves.
+          reqLog.error("error page render failed", { error: renderErr instanceof Error ? (renderErr.stack ?? renderErr.message) : String(renderErr) });
+          return void res.writeHead(err.status, { "content-type": "text/plain; charset=utf-8" }).end("Forbidden");
+        }
       }
       reqLog.error("unhandled request error", { error: err instanceof Error ? (err.stack ?? err.message) : String(err) });
       if (res.headersSent) return void res.end(); // a partial body is already on the wire

src/i18n/locales/en-US.ts

@@ -141,7 +141,7 @@ const messages = {
   "pagination.go": "Go",
   "pagination.label": "Pagination",
   "pagination.next": "Next page",
-  "pagination.of": "of",
+  "pagination.summary": "{{from}}–{{to}} of <b>{{total}}</b>",
   "pagination.previous": "Previous page",
   "pagination.rows": "Rows",
 

src/i18n/locales/sv-SE.ts

@@ -127,7 +127,7 @@ const messages: CoreMessages = {
   "pagination.go": "Visa",
   "pagination.label": "Sidnavigering",
   "pagination.next": "Nästa sida",
-  "pagination.of": "av",
+  "pagination.summary": "{{from}}–{{to}} av <b>{{total}}</b>",
   "pagination.previous": "Föregående sida",
   "pagination.rows": "Rader",
 

views/partials/pagination.ejs

@@ -3,7 +3,7 @@
   Page items are <a>, inert ones (current/ellipsis/disabled) aren't.
   Config (all optional; never throws):
     label?    nav aria-label (default "Pagination")
-    summary?  { from, to, total }                                        → "from–to of <b>total</b>"
+    summary?  { from, to, total }                                        → the pagination.summary message
     rows?     { name, value?, options, label?, submitLabel?, action?, hidden? }   rows-per-page form
                 options: (number | { value, label })[]; hidden: { name, value }[] carries list state
     prev?, next?  { href? }                                              page step; omit href ⇒ disabled
@@ -21,7 +21,7 @@
 -%>
 <footer class="pager">
 <% if (summary) { -%>
-  <span><%= summary.from %>–<%= summary.to %> <%= t("pagination.of") %> <b><%= summary.total %></b></span>
+  <span><%- t("pagination.summary", { from: summary.from, to: summary.to, total: summary.total }) %></span>
 <% } -%>
 <% if (rows) { -%>
   <form class="pager-rows" method="get"<% if (rows.action) { %> action="<%= localeHref(rows.action) %>"<% } %>>