test(bible): skip corpus-dependent tests when optional corpora aren't embedded

Since 51c0f4e split the corpora (only vul embedded by default; wuj/drb/grb
behind -tags fullbible), `go test ./...` on the default build was red across six
packages -- every failure was a test assuming an optional corpus is present.

Guard those assertions with a skip keyed on bible.Meta(code), so they run under
-tags fullbible and skip -- not fail -- on the default vul-only build. Mixed
tests are split into subtests so the always-embedded vul assertions and pure
logic (pl->vul fallback, explicit passthrough, bt-rejection, i18n labels) keep
running on both builds. Test-only change; no product code or corpora touched.

- internal/bible: TestVerses, TestLookup, TestCorpusBooks, TestChapters,
  TestGrbNoApparatusMarkers, TestCrossChapterRange* (requireCorpus helper).
- internal/cli, config, render, tui, web: the same pattern for their
  corpus-dependent tests.
- Fixes an index-out-of-range panic in internal/tui's reader tests that was
  aborting the package binary and masking 3 further corpus-absence failures
  (TestReaderBookmarkFlow, TestReaderChapterJump, TestReaderRemembersPlace).

Verified: `go test ./...` and `go test -tags fullbible ./...` both green (0 FAIL);
guards active only on the default build (29 skips vs 1 unrelated pre-existing);
gofmt and go vet clean.

1 files changed, 36 insertions, 12 deletions

diff --git a/internal/render/render_test.go b/internal/render/render_test.go
index dd177bb..e3bdc5d 100644
--- a/internal/render/render_test.go
+++ b/internal/render/render_test.go
@@ -4,20 +4,39 @@ import (
 	"strings"
 	"testing"
 
+	"github.com/lukaszkasprzak/lectio/internal/bible"
 	"github.com/lukaszkasprzak/lectio/internal/liturgy"
 )
 
+// requireCorpus skips the test when corpus `code` is not embedded in this
+// build. The optional corpora (wuj, drb, grb) compile in only with
+// `-tags fullbible` (or when dropped into the user corpora dir); mirrors the
+// helper in internal/bible so these tests run under fullbible and skip -- not
+// fail -- on the default vul-only build.
+func requireCorpus(t *testing.T, code string) {
+	t.Helper()
+	if _, ok := bible.Meta(code); !ok {
+		t.Skipf("corpus %q not embedded; build with -tags fullbible", code)
+	}
+}
+
 func TestGatherBible(t *testing.T) {
 	// Offline sections carry the English-canonical lookup reference in Ref; the
 	// display citation stays in the reader's sigla dialect.
 	sec := liturgy.Section{Heading: "Ewangelia", Citation: "J 20, 1. 11-18", Ref: "John 20:1,11-18"}
 	label, blocks := GatherVersion("wuj", sec, "new", "pl")
+	// The label is an i18n chrome string, independent of whether the corpus is
+	// embedded, so it must resolve on either build.
 	if !strings.Contains(label, "Wujek") {
 		t.Errorf("label = %q", label)
 	}
-	if len(blocks) == 0 || !strings.HasPrefix(blocks[0], "20:1") {
-		t.Errorf("first block = %q", blocks)
-	}
+	// The verse blocks come from the wuj corpus text itself.
+	t.Run("verses", func(t *testing.T) {
+		requireCorpus(t, "wuj")
+		if len(blocks) == 0 || !strings.HasPrefix(blocks[0], "20:1") {
+			t.Errorf("first block = %q", blocks)
+		}
+	})
 }
 
 func TestGatherTraditional(t *testing.T) {
@@ -106,18 +125,23 @@ func TestOfflineVersions(t *testing.T) {
 func TestGatherVersesBible(t *testing.T) {
 	sec := liturgy.Section{Heading: "Ewangelia", Citation: "J 20, 1. 11-18", Ref: "John 20:1,11-18"}
 	label, verses, versified := GatherVerses("wuj", sec, "new", "pl")
+	// The label is an i18n chrome string, independent of the corpus.
 	if !strings.Contains(label, "Wujek") {
 		t.Errorf("label = %q", label)
 	}
-	if !versified {
-		t.Error("versified = false, want true for wuj with a resolvable citation")
-	}
-	if len(verses) == 0 {
-		t.Fatal("verses empty")
-	}
-	if verses[0].Chapter != 20 || verses[0].Verse != 1 || verses[0].Text == "" {
-		t.Errorf("verses[0] = %+v", verses[0])
-	}
+	// Versified extraction requires the wuj corpus text.
+	t.Run("verses", func(t *testing.T) {
+		requireCorpus(t, "wuj")
+		if !versified {
+			t.Error("versified = false, want true for wuj with a resolvable citation")
+		}
+		if len(verses) == 0 {
+			t.Fatal("verses empty")
+		}
+		if verses[0].Chapter != 20 || verses[0].Verse != 1 || verses[0].Text == "" {
+			t.Errorf("verses[0] = %+v", verses[0])
+		}
+	})
 }
 
 func TestGatherVersesBT(t *testing.T) {