refactor: remove the niedziela/missalemeum scrapers, bt, traditional_lang

The daily view now computes entirely offline (previous commit), so retire the
network path and everything that served it:

- Delete internal/tradlit (missalemeum) and the niedziela scraper from
  internal/liturgy (fetch/store/parse + fixtures); keep Section, DayInfo and
  ExtractCitation.
- Remove the "bt" version everywhere (render gatherBT + branches, config,
  i18n, web form, TUI) and bible.ToEnglishRef (Polish citation converter).
  A legacy config carrying "bt" migrates to "wuj" on load (config.migrateBT).
- Remove the traditional_lang config field and the -g/--lang flag from all
  three binaries.
- Drop the now-dead flags -R/--refresh, -o/--offline, -u/--update,
  -C/--clean and the harvest/clean commands.
- New defaults: versions = wuj,vul,grb,drb; default_version = vul.

Update the README (offline-by-design, no harvest/update), help text, and
stale niedziela/bt doc comments. Tests updated for the offline reality;
go test ./... and go vet ./... are clean, all three binaries build and run
offline (OF + EF, compare, web).

1 files changed, 6 insertions, 10 deletions

diff --git a/internal/i18n/i18n.go b/internal/i18n/i18n.go
index 36aa288..f2221b6 100644
--- a/internal/i18n/i18n.go
+++ b/internal/i18n/i18n.go
@@ -8,7 +8,7 @@ package i18n
 // UI is one language's complete set of chrome strings.
 type UI struct {
 	// Version names each bible version for column headers / prose, keyed by
-	// version code (bt, wuj, vul, grb, drb).
+	// version code (wuj, vul, grb, drb).
 	Version map[string]string
 
 	// PartLabel names each modern-lectionary section's heading label word,
@@ -74,7 +74,7 @@ type UI struct {
 
 	// Web /settings page labels (the ones without an existing shared field):
 	// the saved confirmation, the config-field labels, and the save button.
-	WebSaved, WebTradLang, WebUILang, WebSiglaStyle, WebDefaultVersion   string
+	WebSaved, WebUILang, WebSiglaStyle, WebDefaultVersion                string
 	WebVersions, WebWebVersions, WebOffline, WebWidth, WebPort, WebPager string
 	WebSave                                                              string
 
@@ -106,7 +106,6 @@ func Get(lang string) UI {
 
 var enUI = UI{
 	Version: map[string]string{
-		"bt":  "Biblia Tysiąclecia (niedziela.pl)",
 		"wuj": "Wujek (Polish)",
 		"vul": "Vulgate (Latin)",
 		"grb": "Greek",
@@ -119,11 +118,11 @@ var enUI = UI{
 		"aklamacja":         "Acclamation",
 		"ewangelia":         "Gospel",
 	},
-	FooterKeys:            "tab/⇧tab version  ←/→ day  d date  j/k scroll  space/b page  g/G top/bottom  r refresh  q quit",
+	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 (←/→) or refresh (r)",
+	ErrorHint:             "change date (←/→)",
 	JumpPrompt:            "go to date (YYYY-MM-DD)",
 	ReaderTitle:           "reader — pick a book",
 	ReaderPickKeys:        "type to filter  ↑/↓ move  enter open  esc quit",
@@ -172,7 +171,6 @@ var enUI = UI{
 	WebNoBookmarks:        "No bookmarks yet.",
 	WebDelete:             "delete",
 	WebSaved:              "Saved.",
-	WebTradLang:           "traditional language",
 	WebUILang:             "UI language",
 	WebSiglaStyle:         "sigla style",
 	WebDefaultVersion:     "default version",
@@ -194,7 +192,6 @@ var enUI = UI{
 
 var plUI = UI{
 	Version: map[string]string{
-		"bt":  "Biblia Tysiąclecia (niedziela.pl)",
 		"wuj": "Wujek (pol.)",
 		"vul": "Wulgata (lac.)",
 		"grb": "Grecki",
@@ -207,11 +204,11 @@ var plUI = UI{
 		"aklamacja":         "Aklamacja",
 		"ewangelia":         "Ewangelia",
 	},
-	FooterKeys:            "tab/⇧tab wersja  ←/→ dzień  d data  j/k przewiń  spacja/b strona  g/G góra/dół  r odśwież  q wyjście",
+	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 (←/→) lub odśwież (r)",
+	ErrorHint:             "zmień datę (←/→)",
 	JumpPrompt:            "przejdź do daty (RRRR-MM-DD)",
 	ReaderTitle:           "czytnik — wybierz księgę",
 	ReaderPickKeys:        "wpisz, by filtrować  ↑/↓ ruch  enter otwórz  esc wyjście",
@@ -260,7 +257,6 @@ var plUI = UI{
 	WebNoBookmarks:        "Brak zakładek.",
 	WebDelete:             "usuń",
 	WebSaved:              "Zapisano.",
-	WebTradLang:           "język tradycyjny",
 	WebUILang:             "język interfejsu",
 	WebSiglaStyle:         "styl sigli",
 	WebDefaultVersion:     "wersja domyślna",