i18n: make all UI chrome user-translatable via ui/<code>.ini

The interface chrome (version labels, TUI keybar/messages, CLI banner words,
web control labels, section-heading words) was English/Polish hardcoded in Go.
It is now data: the English and Polish tables ship as embedded lang/en.ini and
lang/pl.ini, and any language is user-overridable at <config>/ui/<code>.ini,
resolved per key with an English fallback. With ui_language = <code> plus a
names/<code>.ini, the WHOLE interface -- chrome, day names, saint names -- is
translatable without a rebuild.

- i18n.Get loads the embedded English baseline, overlays the embedded/user
  language file, caches per lang; field <-> INI-key mapping is by reflection
  (lang.go) so the tables and files stay in sync automatically. Edge-space
  values (e.g. "error: ") are double-quoted so the INI trim keeps them. The
  Go tables move to golden_test.go; TestGoldenMatchesEmbedded asserts the
  embedded files still parse back to them, and TestGenerateLangFiles
  regenerates them (LECTIO_GEN=1).
- config.UIDir(); wire i18n.SetUserDir in the CLI, TUI and web entry points.
- README/config: document ui/<code>.ini alongside names/<code>.ini.

1 files changed, 9 insertions, 186 deletions

diff --git a/internal/i18n/i18n.go b/internal/i18n/i18n.go
index f2221b6..1589476 100644
--- a/internal/i18n/i18n.go
+++ b/internal/i18n/i18n.go
@@ -1,8 +1,12 @@
-// Package i18n holds lectio's UI-chrome string tables (English and Polish)
-// for the ui_language config setting. It localises the chrome only --
-// version-column labels, the TUI keybar/messages, the CLI banner words, the
-// web control labels, and the modern-lectionary section-heading label words
-// -- never the scripture verse text or citation, which stay source-language.
+// Package i18n holds lectio's UI-chrome strings -- the version-column labels,
+// the TUI keybar/messages, the CLI banner words, the web control labels, and the
+// modern-lectionary section-heading label words. It localises the chrome only,
+// never the scripture verse text or citation, which stay source-language.
+//
+// English is the built-in baseline and Polish ships embedded (lang/en.ini,
+// lang/pl.ini). Any language is user-overridable at <config>/ui/<code>.ini,
+// resolved per key with an English fallback (see lang.go / Get), so a user can
+// translate the whole interface for their language without a rebuild.
 package i18n
 
 // UI is one language's complete set of chrome strings.
@@ -94,184 +98,3 @@ type UI struct {
 	// errors.Unwrap-ability, both format identically via Error()).
 	NoVersion, NoVersionPartial, NoReference, NoReferenceErr string
 }
-
-// Get returns lang's chrome string set, falling back to English for
-// anything other than "pl".
-func Get(lang string) UI {
-	if lang == "pl" {
-		return plUI
-	}
-	return enUI
-}
-
-var enUI = UI{
-	Version: map[string]string{
-		"wuj": "Wujek (Polish)",
-		"vul": "Vulgate (Latin)",
-		"grb": "Greek",
-		"drb": "Douay-Rheims (English)",
-	},
-	PartLabel: map[string]string{
-		"pierwsze_czytanie": "1st reading",
-		"psalm":             "Psalm",
-		"drugie_czytanie":   "2nd reading",
-		"aklamacja":         "Acclamation",
-		"ewangelia":         "Gospel",
-	},
-	FooterKeys:            "tab/⇧tab version  ←/→ day  d date  j/k scroll  space/b page  g/G top/bottom  q quit",
-	Loading:               "loading…",
-	NoReadingsFor:         "no readings for ",
-	ErrorPrefix:           "error: ",
-	ErrorHint:             "change date (←/→)",
-	JumpPrompt:            "go to date (YYYY-MM-DD)",
-	ReaderTitle:           "reader — pick a book",
-	ReaderPickKeys:        "type to filter  ↑/↓ move  enter open  esc quit",
-	ReaderReadKeys:        "n/p chapter  c go-to  tab version  j/k scroll  m mark  b bookmarks  esc books  q quit",
-	ReaderNoText:          "(no text in this version)",
-	ReaderNoMatch:         "(no matching books)",
-	ReaderMarkPrompt:      "note (enter to save, esc to cancel)",
-	ReaderBookmarksTitle:  "bookmarks",
-	ReaderBookmarksKeys:   "j/k move  enter open  d delete  esc back  q quit",
-	ReaderNoBookmarks:     "no bookmarks yet — press m while reading",
-	ReaderMarkVerseKeys:   "↑/↓ pick verse  enter add note  esc cancel",
-	ReaderConfirmDelete:   "Delete this bookmark?",
-	ReaderConfirmKeys:     "y = delete    n = cancel",
-	ReaderMarkNote:        "note",
-	ReaderMarkTags:        "tags",
-	ReaderMarkHelp:        "enter save · tab switch field · esc cancel",
-	ReaderJumpChapter:     "go to chapter",
-	ReaderJumpChapterKeys: "enter go · esc cancel",
-	BannerGospel:          "Gospel",
-	BannerReadings:        "Readings",
-	BannerConnective:      "for",
-	Months:                [12]string{"January", "February", "March", "April", "May", "June", "July", "August", "September", "October", "November", "December"},
-	Lectionary:            "lectionary",
-	OptModern:             "modern",
-	OptTraditional:        "traditional",
-	Parts:                 "parts",
-	OptGospel:             "Gospel",
-	OptAll:                "all parts",
-	Layout:                "layout",
-	OptHorizontal:         "horizontal",
-	OptColumns:            "columns",
-	OptInterlinear:        "interlinear",
-	Theme:                 "theme",
-	Mono:                  "mono",
-	NoInterlinearVerses:   "(no verses to align)",
-	NavReader:             "reader",
-	WebBook:               "book",
-	WebChapter:            "chapter",
-	NavHome:               "home",
-	NavSettings:           "settings",
-	NavBookmarks:          "bookmarks",
-	WebVerseOptional:      "verse (optional)",
-	WebTagsPlaceholder:    "tags, comma-separated",
-	WebAddBookmark:        "bookmark",
-	WebAllTags:            "all",
-	WebNoBookmarks:        "No bookmarks yet.",
-	WebDelete:             "delete",
-	WebSaved:              "Saved.",
-	WebUILang:             "UI language",
-	WebSiglaStyle:         "sigla style",
-	WebDefaultVersion:     "default version",
-	WebVersions:           "versions",
-	WebWebVersions:        "web versions",
-	WebOffline:            "offline",
-	WebWidth:              "width",
-	WebPort:               "web port",
-	WebPager:              "pager",
-	WebSave:               "Save",
-	Export:                "download",
-	Calendar:              "month calendar",
-	NoReadingsDay:         "no readings for this day",
-	NoVersion:             "(not in %s)",
-	NoVersionPartial:      "(not in %s: %s)",
-	NoReference:           "(no reference)",
-	NoReferenceErr:        "(no reference: %v)",
-}
-
-var plUI = UI{
-	Version: map[string]string{
-		"wuj": "Wujek (pol.)",
-		"vul": "Wulgata (lac.)",
-		"grb": "Grecki",
-		"drb": "Douay-Rheims (ang.)",
-	},
-	PartLabel: map[string]string{
-		"pierwsze_czytanie": "1. czytanie",
-		"psalm":             "Psalm",
-		"drugie_czytanie":   "2. czytanie",
-		"aklamacja":         "Aklamacja",
-		"ewangelia":         "Ewangelia",
-	},
-	FooterKeys:            "tab/⇧tab wersja  ←/→ dzień  d data  j/k przewiń  spacja/b strona  g/G góra/dół  q wyjście",
-	Loading:               "ładowanie…",
-	NoReadingsFor:         "brak czytań na ",
-	ErrorPrefix:           "błąd: ",
-	ErrorHint:             "zmień datę (←/→)",
-	JumpPrompt:            "przejdź do daty (RRRR-MM-DD)",
-	ReaderTitle:           "czytnik — wybierz księgę",
-	ReaderPickKeys:        "wpisz, by filtrować  ↑/↓ ruch  enter otwórz  esc wyjście",
-	ReaderReadKeys:        "n/p rozdział  c skok  tab wersja  j/k przewiń  m zakładka  b zakładki  esc księgi  q wyjście",
-	ReaderNoText:          "(brak tekstu w tej wersji)",
-	ReaderNoMatch:         "(brak pasujących ksiąg)",
-	ReaderMarkPrompt:      "notatka (enter zapisz, esc anuluj)",
-	ReaderBookmarksTitle:  "zakładki",
-	ReaderBookmarksKeys:   "j/k ruch  enter otwórz  d usuń  esc wróć  q wyjście",
-	ReaderNoBookmarks:     "brak zakładek — naciśnij m podczas czytania",
-	ReaderMarkVerseKeys:   "↑/↓ wybierz werset  enter notatka  esc anuluj",
-	ReaderConfirmDelete:   "Usunąć zakładkę?",
-	ReaderConfirmKeys:     "y = usuń    n = anuluj",
-	ReaderMarkNote:        "notatka",
-	ReaderMarkTags:        "tagi",
-	ReaderMarkHelp:        "enter zapisz · tab pole · esc anuluj",
-	ReaderJumpChapter:     "przejdź do rozdziału",
-	ReaderJumpChapterKeys: "enter przejdź · esc anuluj",
-	BannerGospel:          "Ewangelia",
-	BannerReadings:        "Czytania",
-	BannerConnective:      "na",
-	Months:                [12]string{"Styczeń", "Luty", "Marzec", "Kwiecień", "Maj", "Czerwiec", "Lipiec", "Sierpień", "Wrzesień", "Październik", "Listopad", "Grudzień"},
-	Lectionary:            "lekcjonarz",
-	OptModern:             "nowy",
-	OptTraditional:        "tradycyjny",
-	Parts:                 "zakres",
-	OptGospel:             "Ewangelia",
-	OptAll:                "wszystkie części",
-	Layout:                "układ",
-	OptHorizontal:         "poziomo",
-	OptColumns:            "kolumny",
-	OptInterlinear:        "interlinearnie",
-	Theme:                 "motyw",
-	Mono:                  "mono",
-	NoInterlinearVerses:   "(brak wersetów do zestawienia interlinearnego)",
-	NavReader:             "czytnik",
-	WebBook:               "księga",
-	WebChapter:            "rozdział",
-	NavHome:               "strona główna",
-	NavSettings:           "ustawienia",
-	NavBookmarks:          "zakładki",
-	WebVerseOptional:      "werset (opcjonalnie)",
-	WebTagsPlaceholder:    "tagi, oddzielone przecinkami",
-	WebAddBookmark:        "zakładka",
-	WebAllTags:            "wszystkie",
-	WebNoBookmarks:        "Brak zakładek.",
-	WebDelete:             "usuń",
-	WebSaved:              "Zapisano.",
-	WebUILang:             "język interfejsu",
-	WebSiglaStyle:         "styl sigli",
-	WebDefaultVersion:     "wersja domyślna",
-	WebVersions:           "wersje",
-	WebWebVersions:        "wersje web",
-	WebOffline:            "offline",
-	WebWidth:              "szerokość",
-	WebPort:               "port web",
-	WebPager:              "pager",
-	WebSave:               "Zapisz",
-	Export:                "pobierz",
-	Calendar:              "kalendarz miesiąca",
-	NoReadingsDay:         "brak czytań na ten dzień",
-	NoVersion:             "(brak w „%s”)",
-	NoVersionPartial:      "(brak w „%s”: %s)",
-	NoReference:           "(brak odwołania)",
-	NoReferenceErr:        "(brak odwołania: %w)",
-}