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, 38 insertions, 1 deletions

diff --git a/internal/config/config_test.go b/internal/config/config_test.go
index 3830cb6..14823b8 100644
--- a/internal/config/config_test.go
+++ b/internal/config/config_test.go
@@ -13,9 +13,20 @@ func TestLoadSeeds(t *testing.T) {
 	if err != nil {
 		t.Fatal(err)
 	}
-	if cfg.DefaultVersion != "bt" || cfg.Offline {
+	if cfg.DefaultVersion != "vul" || cfg.Offline {
 		t.Errorf("defaults wrong: %+v", cfg)
 	}
+	wantVersions := []string{"wuj", "vul", "grb", "drb"}
+	if len(cfg.Versions) != len(wantVersions) {
+		t.Errorf("versions default = %v, want %v", cfg.Versions, wantVersions)
+	} else {
+		for i, v := range wantVersions {
+			if cfg.Versions[i] != v {
+				t.Errorf("versions default = %v, want %v", cfg.Versions, wantVersions)
+				break
+			}
+		}
+	}
 	if cfg.Lectionary != "new" {
 		t.Errorf("lectionary default wrong: %+v", cfg)
 	}
@@ -24,6 +35,32 @@ func TestLoadSeeds(t *testing.T) {
 	}
 }
 
+// TestLoadMigratesBT checks a legacy config still carrying the retired "bt"
+// version (both as default_version and in the versions list) loads and is
+// migrated to wuj: bt is dropped from the list when wuj is already present
+// (no duplicate column) and default_version bt becomes wuj.
+func TestLoadMigratesBT(t *testing.T) {
+	dir := t.TempDir()
+	t.Setenv("LECTIO_CONFIG", filepath.Join(dir, "config.ini"))
+	os.WriteFile(filepath.Join(dir, "config.ini"),
+		[]byte("default_version = bt\nversions = bt, wuj, vul\n"), 0o644)
+	cfg, err := Load()
+	if err != nil {
+		t.Fatal(err)
+	}
+	if cfg.DefaultVersion != "wuj" {
+		t.Errorf("default_version bt not migrated: %q", cfg.DefaultVersion)
+	}
+	for _, v := range cfg.Versions {
+		if v == "bt" {
+			t.Errorf("versions still carries bt: %v", cfg.Versions)
+		}
+	}
+	if len(cfg.Versions) != 2 || cfg.Versions[0] != "wuj" || cfg.Versions[1] != "vul" {
+		t.Errorf("versions after migration = %v, want [wuj vul]", cfg.Versions)
+	}
+}
+
 func TestLoadOverride(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("XDG_CONFIG_HOME", dir)