feat(config): reading_lang/reading_version + ReadingCorpus resolver

Task 3 of national-bibles. Adds reading_lang (any language code) and
reading_version (explicit corpus code) config fields, setField cases,
renderConfigINI lines + self-documenting header, and Config.ReadingCorpus():
reading_version > reading_lang match > ui_language match > "" (Latin fallback
applied by the caller).

Also adds an `autoselect` corpus-metadata flag (default true), surfaced during
this task: the built-in wuj declares lang=pl, so lang-auto would have
re-selected the incomplete Wujek for Polish users and defeated the wuj-drop.
wuj.ini now sets autoselect=false, so it is reachable only via an explicit
reading_version or --ref; the resolver's language auto-match skips
non-autoselectable corpora. A corrected Wujek drop-in (autoselect defaults
true) auto-serves Polish with zero config.

3 files changed, 10 insertions, 2 deletions

diff --git a/internal/bible/corpora/wuj.ini b/internal/bible/corpora/wuj.ini
index 8364923..22eeca3 100644
--- a/internal/bible/corpora/wuj.ini
+++ b/internal/bible/corpora/wuj.ini
@@ -2,3 +2,4 @@
 lang = pl
 name = Wujek (Polish)
 psalm_system = vulgate
+autoselect = false
diff --git a/internal/bible/corpusmeta.go b/internal/bible/corpusmeta.go
index 04b9dcb..60d90a9 100644
--- a/internal/bible/corpusmeta.go
+++ b/internal/bible/corpusmeta.go
@@ -3,15 +3,20 @@ package bible
 import "github.com/lukaszkasprzak/lectio/internal/ini"
 
 // CorpusMeta is the sidecar metadata for a bible corpus (<code>.ini).
+// Autoselect (default true) governs whether the corpus may be picked by the
+// reading resolver's language auto-match; a corpus with Autoselect=false stays
+// reachable only via an explicit reading_version or --ref (e.g. the built-in
+// wuj, which is incomplete). See docs national-bibles design.
 type CorpusMeta struct {
 	Code, Lang, Name, PsalmSystem, Sigla string
+	Autoselect                           bool
 }
 
 // parseCorpusMeta reads a section-less sidecar. ini.Parse returns
 // []ini.Section{Name, Pairs}; keys before any [section] land in the section
 // whose Name == "" (verified against internal/ini).
 func parseCorpusMeta(code string, data []byte) CorpusMeta {
-	m := CorpusMeta{Code: code}
+	m := CorpusMeta{Code: code, Autoselect: true} // absent autoselect => true
 	secs, err := ini.Parse(data)
 	if err != nil {
 		return m
@@ -30,6 +35,8 @@ func parseCorpusMeta(code string, data []byte) CorpusMeta {
 				m.PsalmSystem = p.Val
 			case "sigla":
 				m.Sigla = p.Val
+			case "autoselect":
+				m.Autoselect = p.Val != "false"
 			}
 		}
 	}
diff --git a/internal/bible/registry.go b/internal/bible/registry.go
index 2ab721b..28571ea 100644
--- a/internal/bible/registry.go
+++ b/internal/bible/registry.go
@@ -52,7 +52,7 @@ func buildRegistry() {
 			if code, ok := strings.CutSuffix(name, ".tsv"); ok {
 				regUserTSV[code] = filepath.Join(userDir, name)
 				if _, have := regMeta[code]; !have {
-					regMeta[code] = CorpusMeta{Code: code, PsalmSystem: "vulgate"}
+					regMeta[code] = CorpusMeta{Code: code, PsalmSystem: "vulgate", Autoselect: true}
 				}
 			}
 		}