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, 31 insertions, 14 deletions

diff --git a/internal/web/render_test.go b/internal/web/render_test.go
index 39bcc58..94d5e6e 100644
--- a/internal/web/render_test.go
+++ b/internal/web/render_test.go
@@ -124,26 +124,37 @@ func TestRenderReadingsInterlinear(t *testing.T) {
 		t.Errorf("interlinear output missing vnum: %q", html[:min(300, len(html))])
 	}
 	// The first ilverse block should group both version labels under one key.
-	// Bound it by the next vnum span (each ilverse carries exactly one).
-	i := strings.Index(html, `class="vnum"`)
-	block := html[i:]
-	if j := strings.Index(html[i+1:], `class="vnum"`); j != -1 {
-		block = html[i : i+1+j]
-	}
-	if !strings.Contains(block, "Wujek") || !strings.Contains(block, "Wulgata") {
-		t.Errorf("first interlinear verse block missing both version labels: %q", block)
-	}
+	// Bound it by the next vnum span (each ilverse carries exactly one). The
+	// Wujek line appears only when the optional wuj corpus is embedded and
+	// contributes versified text to the alignment.
+	t.Run("both version labels", func(t *testing.T) {
+		requireCorpus(t, "wuj")
+		i := strings.Index(html, `class="vnum"`)
+		block := html[i:]
+		if j := strings.Index(html[i+1:], `class="vnum"`); j != -1 {
+			block = html[i : i+1+j]
+		}
+		if !strings.Contains(block, "Wujek") || !strings.Contains(block, "Wulgata") {
+			t.Errorf("first interlinear verse block missing both version labels: %q", block)
+		}
+	})
 }
 
 func TestRenderReadingsInterlinearExcludesBT(t *testing.T) {
 	secs := []liturgy.Section{{Heading: "Ewangelia", Citation: "J 20, 1. 11-18", Ref: "John 20:1,11-18", PartID: "ewangelia"}}
 	html := string(RenderReadings(secs, []string{"bt", "vul"}, "new", "interlinear", "pl", liturgy.DayInfo{}))
+	// bt is dropped before rendering regardless, so its own label never shows.
 	if strings.Contains(html, "Biblia Tysiąclecia (niedziela.pl)") {
 		t.Errorf("interlinear output should substitute wuj for bt, not carry bt's label: %q", html[:min(300, len(html))])
 	}
-	if !strings.Contains(html, "Wujek") {
-		t.Errorf("interlinear output should substitute wuj for bt: %q", html[:min(300, len(html))])
-	}
+	// bt maps to wuj, but the Wujek label only renders when wuj is embedded and
+	// supplies versified text to the alignment.
+	t.Run("wuj substituted", func(t *testing.T) {
+		requireCorpus(t, "wuj")
+		if !strings.Contains(html, "Wujek") {
+			t.Errorf("interlinear output should substitute wuj for bt: %q", html[:min(300, len(html))])
+		}
+	})
 }
 
 func TestRenderReadingsInterlinearNoVersifiedNote(t *testing.T) {
@@ -190,9 +201,15 @@ func TestRenderReadingsLocalizesEN(t *testing.T) {
 
 func TestRenderPassageColumns(t *testing.T) {
 	html := string(RenderPassage("John", "John", 3, []string{"wuj"}, "vertical", "en"))
-	if !strings.Contains(html, "John 3") || !strings.Contains(html, "3:16") {
-		t.Errorf("passage columns missing heading/verse:\n%s", html)
+	if !strings.Contains(html, "John 3") { // passage heading, independent of the corpus
+		t.Errorf("passage columns missing heading:\n%s", html)
 	}
+	t.Run("verse", func(t *testing.T) {
+		requireCorpus(t, "wuj") // the verse text comes from the optional wuj corpus
+		if !strings.Contains(html, "3:16") {
+			t.Errorf("passage columns missing verse:\n%s", html)
+		}
+	})
 }
 
 func TestRenderPassageInterlinear(t *testing.T) {