fix(editor): a missing translation must not become a document error

[chaxus]

Reported in Korean: opening a blank document showed the vendor's modal "An error occurred while working with the document. Use the 'Download as' option to save a backup copy" — before typing anything. Reproduced in a production build; only ko, and every time.

Cause

DE.Views.Statusbar.tipMultiplePages is in en.json and not in ko.json, and unlike most strings it has no default in the component's own source — so the property is undefined. The status bar hands it to a tooltip setter that does not check:

updateHint: function (t) { ... "string" == typeof t ? t : t[0] ... }

undefined[0] throws inside the view layer, the app catches it as a document error, and the user is told to save a backup of a document they have not written yet.

This is not one bad file: all 44 non-English locales are short against en.json, from 1 key to 3167. Korean simply lost the lottery of which gap reaches a tooltip setter.

app	zh	ja	ko	de	es	pt
documenteditor	17	16	22	1	1	16
spreadsheeteditor	0	552	50	0	25	0
presentationeditor	0	305	0	0	0	0
pdfeditor	71	36	72	36	36	36

Two defences

1. bin/locale-fill.mjs backfills, from en.json, every key missing in the locales this site is translated into — 17 files, ~113 KB, keeping the vendor's minified formatting (pretty-printing would have added ~25 KB per file to a 600 MB tree). bin/build.sh runs it before the vendor tree is hashed into VENDOR_VERSION, and test/unit/vendor-locale.test.ts fails when it has not been run — which is exactly what the next vendor upgrade will do.
2. Guard 11 (guards/hint-fallback.ts) makes updateHint(undefined) a no-op. That covers the other 38 locales, which ?locale= can still select, and whatever the next upgrade breaks.

An English tooltip is a blemish. A modal error on an empty document is someone deciding this editor cannot be trusted with their file.

Test

test/e2e/editor-locales.spec.ts opens a blank document in each of the six non-English site languages and fails on a vendor dialog. Nothing in the suite covered this, because everything else opens the editor in English.

Reverse-checked both defences separately:

• key removed and guard disabled → the ko case fails with the reported dialog
• key removed, guard in place → passes

🤖 Generated with Claude Code

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