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, 2 insertions, 2 deletions

diff --git a/internal/web/templates/index.html b/internal/web/templates/index.html
index c8a48ed..762ed7b 100644
--- a/internal/web/templates/index.html
+++ b/internal/web/templates/index.html
@@ -36,14 +36,14 @@
     </span>
 
     <label>{{.L.Lectionary}}
-      <select name="lectionary" onchange="var b=document.getElementById('ver-bt');if(b)b.style.display=this.value==='traditional'?'none':'';">
+      <select name="lectionary">
         <option value="new" {{if eq .Lectionary "new"}}selected{{end}}>{{.L.OptModern}}</option>
         <option value="traditional" {{if eq .Lectionary "traditional"}}selected{{end}}>{{.L.OptTraditional}}</option>
       </select>
     </label>
 
     {{range .VersionOpts}}
-    <label id="ver-{{.Code}}"{{if and (eq .Code "bt") (eq $.Lectionary "traditional")}} style="display:none"{{end}}><input type="checkbox" name="v" value="{{.Code}}" {{if .Checked}}checked{{end}}> {{.Code}}</label>
+    <label id="ver-{{.Code}}"><input type="checkbox" name="v" value="{{.Code}}" {{if .Checked}}checked{{end}}> {{.Code}}</label>
     {{end}}
 
     <label>{{.L.Parts}}