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.

1 files changed, 1 insertions, 1 deletions

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}
 				}
 			}
 		}