v0.253.0 — errors carry the key of the sentence they are (R-557 slice 2 release B)

179 Hungarian sentences were built deep inside a package with fmt.Errorf and printed by
whoever caught them: too late to translate where they are shown, too early where they are
made. Every one now carries its key across that gap. ZERO Hungarian error literals remain.

util.MsgError does three things at once, each earned:
  - Error() is the Hungarian, byte for byte, so every un-converted printer is unchanged;
  - errors.Is answers for the kind AND for a wrapped cause (KindErrorf dropped the cause);
  - an error ARGUMENT renders recursively, so "formázás sikertelen: %w" translates whole.
A foreign error — restic, docker, ssh, the stdlib — prints verbatim. It is not ours.

76 display sites go through errText, and TestNoErrErrorInPageOutput convicts any that do
not. memoryVerdict returns an error rather than a sentence, so the deploy's 409 and the
household's language come from one value; UpdateRefusal gained a Cause to carry it.

Plurals, one rule, stated once: a key with .one/.other takes its COUNT first. Not a
per-call-site flag — the producer somebody forgot would read "3 app is not running". The
guard caught a real key collision (alert.deadapp.one) the day the rule landed.

TWO DEFECTS FOUND IN MY OWN TOOLING, recorded rather than quietly fixed. The bulk converter
silently dropped multi-line concatenations, damaging 7 producers — and the parity gate could
not see it, because every surviving fragment WAS a real base literal while the CALL had lost
text; two behaviour tests caught it. And the counting script was case-sensitive, so it said
"0 left" while five remained.

MinAgent: 0.131.0 (unchanged). No hub release needed.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0159rPz1ZhFKsS53msqPYxtS

CONTEXT.md

@@ -7,7 +7,9 @@
 >
 > Ask Claude Code: "Please update CONTEXT.md with what we did today"
 
-Last updated: 2026-09-18 (v0.252.0 — localisation slice 2 release A: the sentences the program builds follow the language)
+Last updated: 2026-09-18 (v0.253.0 — localisation slice 2 release B: errors carry a key)
+
+> **2026-09-18 — v0.253.0 (R-557 slice 2 release B).** All **179** Hungarian error messages carry a key (`util.MsgError`): `Error()` is still the Hungarian byte for byte, `errors.Is` answers for the kind AND the wrapped cause, and an inner error argument renders recursively. 76 display sites go through `errText`, pinned by `TestNoErrErrorInPageOutput`. `memoryVerdict` returns an error, `UpdateRefusal` gained a `Cause`. Plurals: a key with `.one`/`.other` takes its count FIRST (bundle rule, not a call-site flag) — the guard caught a real key collision. **Two tooling defects found and recorded:** the bulk converter dropped multi-line concatenations (7 producers; the parity gate could not see it, two behaviour tests could), and my counter was case-sensitive and under-reported. 705 literals left, 0 of them errors.
 
 > **2026-09-18 — v0.252.0 (R-557 slice 2 release A).** The sentences the program BUILDS now follow the language: 226 Go literals converted (flash lines, page data, API answers, alert banners, 237 country names, the four app-named page titles — R-566 closed). Flash travels as a KEY in the redirect URL with `fa` parameters; an old link's prose is still shown verbatim. New gate `i18n_go_parity.py` refuses any key whose Hungarian is not byte-identical to the base commit (7 467 literals frozen; 3 decoys). Wire goldens freeze the report warnings and the event messages the hub MAILS — those stay Hungarian until slice 3 (R-558). Remaining: 894 literals, 176 of them `fmt.Errorf` (release B); persisted text (release C, §16 option 1). New rows R-572/R-573/R-574.