Make the dictionary startup line report rows, not capabilities

It logged dictionary.Langs(), which is a compile-time constant of the languages
DreamDict *supports*. The database deployed until today supported Spanish and
contained none of it, so the line printed a confident "[en fr pt-PT es zh]"
over a file where every Spanish lookup came back empty — the exact failure the
line exists to catch, reported as success.

Contents() counts rows per language instead. For a file somebody has to copy
onto the box by hand, "what is in it" is the only question worth asking, and
the answer is now en=136615 es=102971 fr=56096 pt-PT=136300 zh=120883.

Claude-Session: https://claude.ai/code/session_016y6gyuHkQXPiEuW8RGQyua

internal/lexicon/dreamdict.go

@@ -2,8 +2,10 @@ package lexicon
 
 import (
 	"errors"
+	"fmt"
 	"io/fs"
 	"os"
+	"sort"
 	"strings"
 	"unicode/utf8"
 
@@ -56,9 +58,34 @@ func (dd *DreamDict) Close() error {
 	return dd.d.Close()
 }
 
-// Langs returns the language codes dict.db was built with, so startup can log
-// what it actually got rather than what it hoped for.
-func (dd *DreamDict) Langs() []string { return dictionary.Langs() }
+// Contents reports how many words the open dict.db holds per language, so
+// startup can log what it actually got.
+//
+// It counts rows rather than returning DreamDict's list of supported languages.
+// Those are not the same thing and the difference is the whole point: a
+// database built before Spanish existed still *supports* Spanish, and a log
+// line naming the supported set would have said so cheerfully while every
+// Spanish lookup came back empty. Counting rows is the question worth asking of
+// a file somebody had to copy onto the box by hand.
+func (dd *DreamDict) Contents() string {
+	counts, err := dd.d.WordCount()
+	if err != nil {
+		return "unreadable: " + err.Error()
+	}
+	langs := make([]string, 0, len(counts))
+	for lang := range counts {
+		langs = append(langs, lang)
+	}
+	sort.Strings(langs)
+	parts := make([]string, 0, len(langs))
+	for _, lang := range langs {
+		parts = append(parts, fmt.Sprintf("%s=%d", lang, counts[lang]))
+	}
+	if len(parts) == 0 {
+		return "no words"
+	}
+	return strings.Join(parts, " ")
+}
 
 // dreamProvider serves one writer: English lookups from dict.db, glossed into
 // native. The struct is a value, created per request by [Set.For] — it holds no
@@ -180,8 +207,8 @@ const maxGlossSenses = 3
 //
 // A language dict.db was built without simply has no rows, so this returns "" —
 // which is exactly what an unglossed word returns, and the popover already
-// renders that case. Spanish today is precisely this: supported by DreamDict,
-// absent from the deployed database until it is rebuilt.
+// renders that case. Spanish was precisely this until the database was rebuilt
+// with it on 2026-07-27; the code path did not change, the file did.
 func (p dreamProvider) translate(norm string) (string, error) {
 	for _, c := range candidates(norm) {
 		trs, err := p.dict.d.Equivalents(c, langEN, p.native)

internal/lexicon/dreamdict_test.go

@@ -519,3 +519,25 @@ func TestHandlerDecodesPunctuatedWords(t *testing.T) {
 		t.Errorf("Word = %q, want the decoded word", res.Word)
 	}
 }
+
+func TestContentsCountsRowsNotSupportedLanguages(t *testing.T) {
+	// The fixture is seeded with English and pt-PT only. DreamDict *supports*
+	// French, Spanish and Chinese too — and a startup line that reported the
+	// supported set would have named all five while every French lookup came
+	// back empty. That is the failure this log line exists to catch, so it must
+	// count rows.
+	got := NewSet(openFixture(t))
+	summary := got.Contents()
+	if !strings.Contains(summary, "en=") || !strings.Contains(summary, "pt-PT=") {
+		t.Errorf("Contents = %q, want the languages the fixture actually holds", summary)
+	}
+	for _, absent := range []string{"fr=", "es=", "zh="} {
+		if strings.Contains(summary, absent) {
+			t.Errorf("Contents = %q, must not name %q — no rows exist for it", summary, absent)
+		}
+	}
+	// No dictionary at all still has to answer something printable.
+	if s := NewSet(nil).Contents(); s == "" {
+		t.Error("Contents with no dictionary must still say something")
+	}
+}

internal/lexicon/provider.go

@@ -53,6 +53,16 @@ func NewSet(dream *DreamDict) *Set {
 // usable.
 func (s *Set) HasDreamDict() bool { return s.dream != nil }
 
+// Contents describes what the open dict.db actually holds, for the startup log.
+// With no dictionary it says so rather than returning an empty string, because
+// a blank in a log line is indistinguishable from a bug in the log line.
+func (s *Set) Contents() string {
+	if s.dream == nil {
+		return "no dict.db — embedded datasets only"
+	}
+	return s.dream.Contents()
+}
+
 // For returns the provider that should answer lookups for a writer whose pair
 // language is lang.
 //