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, 15 insertions, 48 deletions

diff --git a/internal/render/render.go b/internal/render/render.go
index 3d685d2..c744aac 100644
--- a/internal/render/render.go
+++ b/internal/render/render.go
@@ -99,22 +99,17 @@ func system(version string) string {
 	return "vulgate"
 }
 
-const incipit = "Słowa Ewangelii"
-
 // GatherVersion returns (label, blocks) for one version of one reading
-// section. Each block is a paragraph (Polish) or a verse line (bible
-// versions); on any failure the blocks hold a single short note instead.
+// section. Each block is a verse line; on any failure the blocks hold a single
+// short note instead.
 //
-// lectionary selects how sec.Citation is read: "new" (modern/niedziela.pl)
-// citations are Polish and go through bible.ToEnglishRef; "traditional"
-// (missalemeum) citations are already English kjv-style and are used as-is.
-// lang selects the UI chrome language the label comes from (see
-// internal/i18n); it never affects the verse text/citation itself.
+// lectionary selects how sec.Ref is renumbered: "new" (Ordinary Form) refs are
+// modern-numbered and go through bible.OFRef for the target Psalter;
+// "traditional" (1962) refs are already Vulgate-numbered and used as-is. lang
+// selects the UI chrome language the label comes from (see internal/i18n); it
+// never affects the verse text/citation itself.
 func GatherVersion(version string, sec liturgy.Section, lectionary, lang string) (label string, blocks []string) {
 	label = versionLabel(version, lang)
-	if version == "bt" {
-		return label, gatherBT(sec)
-	}
 
 	ref, err := resolveRef(version, sec, lectionary, lang)
 	if err != nil {
@@ -170,15 +165,12 @@ func resolveRef(version string, sec liturgy.Section, lectionary, lang string) (s
 }
 
 // GatherVerses returns one version's verses for a section as raw bible.Verse
-// structs (for column/interlinear alignment). versified is false for "bt"
-// (paragraph text, no verse numbers) and on any resolution/lookup failure --
-// callers fall back to GatherVersion's string blocks for those. lang selects
-// the UI chrome language the label comes from, same as GatherVersion.
+// structs (for column/interlinear alignment). versified is false on any
+// resolution/lookup failure -- callers fall back to GatherVersion's string
+// blocks for those. lang selects the UI chrome language the label comes from,
+// same as GatherVersion.
 func GatherVerses(version string, sec liturgy.Section, lectionary, lang string) (label string, verses []bible.Verse, versified bool) {
 	label = versionLabel(version, lang)
-	if version == "bt" {
-		return label, nil, false
-	}
 
 	ref, err := resolveRef(version, sec, lectionary, lang)
 	if err != nil {
@@ -192,35 +184,10 @@ func GatherVerses(version string, sec liturgy.Section, lectionary, lang string)
 	return label, verses, true
 }
 
-// gatherBT returns the section's paragraphs, one block per paragraph, with
-// the liturgical incipit ("Słowa Ewangelii według ...") dropped and repeated
-// blocks (a responsorial psalm's refrain) deduped to their first occurrence.
-func gatherBT(sec liturgy.Section) []string {
-	var blocks []string
-	for _, p := range sec.Paragraphs {
-		b := strings.Join(p, " ")
-		if strings.HasPrefix(b, incipit) {
-			continue
-		}
-		blocks = append(blocks, b)
-	}
-
-	seen := map[string]bool{}
-	deduped := make([]string, 0, len(blocks))
-	for _, b := range blocks {
-		if seen[b] {
-			continue
-		}
-		seen[b] = true
-		deduped = append(deduped, b)
-	}
-	return deduped
-}
-
-// OfflineVersions drops "bt" (which needs the network fetch of the liturgy
-// page) from versions. If "bt" was present but "wuj" (the Polish-language
-// bible version) was not, "wuj" takes bt's place, so the offline set still
-// carries a Polish column.
+// OfflineVersions maps a legacy "bt" version (the retired niedziela.pl scrape,
+// which has no embedded corpus) to "wuj", or drops it when "wuj" is already
+// present so the set keeps a single Polish column. Config load migrates bt out
+// (see config.migrateBT), so this only guards versions passed in directly.
 func OfflineVersions(versions []string) []string {
 	hadWuj := false
 	for _, v := range versions {