Add a known error toast

showKnownErrorToast() in apps/web/src/lib/toast.tsx matches a raw error message against known patterns and enriches the matching ones with a docs link and a copy button. Adding a pattern touches five places, and skipping one leaves either a broken link or an untranslated toast.

Collect first

Ask for anything that is missing before editing:

1. Match string - what the raw error message contains, for example "Origin not allowed". Prefer a stable substring the browser or server actually produces, not a full sentence that varies.
2. i18n key - the errors.* name, for example errors.originNotAllowed.
3. English title - the short user-facing line shown as the toast title.
4. German title - the same in German.
5. Docs anchor - the troubleshooting section that explains the fix.

If the user only describes a symptom, find the real message in the code first (grep the throw site) rather than guessing at the substring.

Step 1 - Troubleshooting section

File: docs/user-guide/troubleshooting.md

Add a ## section with the symptom, the cause, and the fix, matching the surrounding entries. The anchor is the heading lowercased with spaces as hyphens - confirm it, because step 3 hardcodes it.

Step 2 - i18n keys

Add the key inside the "errors" object of apps/web/src/i18n/en.json and de.json by hand:

"errors": {
  "insecureContext": "...",
  "originNotAllowed": "...",
  "yourNewKey": "Your title here"
}

Then add an AI translation to the other 11 locales: es, fi, fr, it, ja, nb, nl, pl, pt-BR, sv, zh.

Check each file's __meta block. A file with "aiGenerated": true needs no extra bookkeeping. A file with "aiGeneratedKeys": [...] needs the new dot-notation key appended to that array.

Step 3 - Detector and handler

File: apps/web/src/lib/toast.tsx

Add the docs URL constant alongside the existing ones:

const YOUR_ERROR_DOCS_URL =
  "https://docs.skysend.app/user-guide/troubleshooting#your-anchor-here";

Add an exported detector after the existing ones:

/**
 * Returns true when ...
 */
export function isYourNewError(message: string): boolean {
  return message.includes("your match string");
}

Add a branch in showKnownErrorToast() before the final toast.error(message) fallback:

if (isYourNewError(message)) {
  showToast(i18n.t("errors.yourNewKey"), {
    type: "error",
    description: message,
    copyText: message,
    docsUrl: YOUR_ERROR_DOCS_URL,
  });
  return;
}

Order matters - a broader pattern placed above a narrower one swallows it. Put the new branch where its match string cannot shadow an existing one.

Step 4 - Developer docs table

File: docs/developer-guide/toast-system.md

Add a row to the known error patterns table under ## showKnownErrorToast():

| `your match string` | `errors.yourNewKey` | [Troubleshooting - Your Title](https://docs.skysend.app/user-guide/troubleshooting#your-anchor) |

Step 5 - Changelog

File: docs/changelog.md, active version block (## vNEXT or the topmost *Release: In Progress*).

One line under ### 🎨 Improvements, describing what the user now sees. Do not name the detector function - entries before v2.11 did, the current style does not.

- **web**: [What triggers the error] now shows a clear message with a link to the fix.

Step 6 - Verify

pnpm --filter @skysend/web build

Then confirm by hand:

• The docs anchor in toast.tsx matches the heading you actually wrote.
• en.json and de.json have the key, and every other locale has it too.
• No existing detector matches your test message first.