feat: books.toml -> books.ini, multi-language (add Latin dialect), config-scoped citation display

books.ini with [en]/[pl]/[la]; parseBooks reads INI (bible drops go-toml).
Latin dialect resolves EF citations (Eccli->Sirach, Apoc->Revelation, Luc...);
sigla_style gains 'latin'. Reading citations now DISPLAY in the configured
sigla (FormatRef(SiglaLang)), not raw English. One-shot books.toml->books.ini
user migration (go-toml now config-only). Web settings editor -> books.ini.

10 files changed, 374 insertions, 68 deletions

diff --git a/cmd/lectio-ui/main.go b/cmd/lectio-ui/main.go
index dd91117..43fc5ab 100644
--- a/cmd/lectio-ui/main.go
+++ b/cmd/lectio-ui/main.go
@@ -120,7 +120,7 @@ func run(args []string, stdout, stderr io.Writer) int {
 
 	var mdl tea.Model = tui.New(cfg, date, bibleVer)
 	if reader {
-		tbl, _ := bible.LoadBookTable(config.UserBooksTOML())
+		tbl, _ := bible.LoadBookTable(config.UserBooksINI())
 		mdl = tui.NewReader(cfg, tbl, bookmarks.Open())
 	}
 	if _, err := tea.NewProgram(mdl, tea.WithAltScreen()).Run(); err != nil {
diff --git a/internal/bible/books.ini b/internal/bible/books.ini
new file mode 100644
index 0000000..5d8f633
--- /dev/null
+++ b/internal/bible/books.ini
@@ -0,0 +1,243 @@
+# lectio book names & abbreviations, per dialect (en, pl, la).
+#
+# This is the built-in default, embedded in the binary. To customise, copy any
+# lines you want to change into ~/.config/lectio/books.ini (next to config.ini).
+# Your file is MERGED over these defaults per book: you only list the books you
+# want to change; every book you don't mention keeps the default below.
+#
+# Each entry is a flat list of forms for one book, in ONE language:
+#   - the FIRST form is the shortcut shown by `lectio --list`
+#   - the LAST form is the full name shown by `lectio --list`
+#   - EVERY form (first, last, and any in between) resolves in `lectio --ref`
+# Resolution is language-scoped and idiomatic: in English mode only the [en]
+# forms resolve (so "Jn" works, "Łk" does not); in Polish mode only [pl].
+#
+# The table KEY is the book's English canonical name -- it must match the Bible
+# corpus, so do not change the keys, only the forms. Books appear in `--list`
+# in scriptural order regardless of the order here.
+
+[en]
+Genesis = Gen, Genesis
+Exodus = Exod, Exodus
+Leviticus = Lev, Leviticus
+Numbers = Num, Numbers
+Deuteronomy = Deut, Deuteronomy
+Joshua = Josh, Joshua
+Judges = Judg, Judges
+Ruth = Ru, Ruth
+1 Samuel = 1 Sam, 1 Samuel
+2 Samuel = 2 Sam, 2 Samuel
+1 Kings = 1 Kgs, 1 Kings
+2 Kings = 2 Kgs, 2 Kings
+1 Chronicles = 1 Chr, 1 Chronicles
+2 Chronicles = 2 Chr, 2 Chronicles
+Ezra = Ezra, Ezra
+Nehemiah = Neh, Nehemiah
+Tobit = Tob, Tobit
+Judith = Jdt, Judith
+Esther = Esth, Esther
+1 Maccabees = 1 Macc, 1 Maccabees
+2 Maccabees = 2 Macc, 2 Maccabees
+Job = Jb, Job
+Psalms = Ps, Psalm, Psalms
+Proverbs = Prov, Proverbs
+Ecclesiastes = Eccl, Ecclesiastes
+Song of Solomon = Song, Song of Songs
+Wisdom = Wis, Wisdom
+Sirach = Sir, Ecclus, Eccli, Ecclesiasticus, Sirach
+Isaiah = Isa, Isaiah
+Jeremiah = Jer, Jeremiah
+Lamentations = Lam, Lamentations
+Baruch = Bar, Baruch
+Ezekiel = Ezek, Ezekiel
+Daniel = Dan, Daniel
+Hosea = Hos, Hosea
+Joel = Jl, Joel
+Amos = Am, Amos
+Obadiah = Obad, Obadiah
+Jonah = Jon, Jonah
+Micah = Mic, Micah
+Nahum = Nah, Nahum
+Habakkuk = Hab, Habakkuk
+Zephaniah = Zeph, Zephaniah
+Haggai = Hag, Haggai
+Zechariah = Zech, Zechariah
+Malachi = Mal, Malachi
+Matthew = Matt, Matthew
+Mark = Mk, Mark
+Luke = Lk, Luke
+John = Jn, John
+The Acts = Acts, Acts
+Romans = Rom, Romans
+1 Corinthians = 1 Cor, 1 Corinthians
+2 Corinthians = 2 Cor, 2 Corinthians
+Galatians = Gal, Galatians
+Ephesians = Eph, Ephesians
+Philippians = Phil, Philippians
+Colossians = Col, Colossians
+1 Thessalonians = 1 Thess, 1 Thessalonians
+2 Thessalonians = 2 Thess, 2 Thessalonians
+1 Timothy = 1 Tim, 1 Timothy
+2 Timothy = 2 Tim, 2 Timothy
+Titus = Ti, Titus
+Philemon = Phlm, Philemon
+Hebrews = Heb, Hebrews
+James = Jas, James
+1 Peter = 1 Pet, 1 Peter
+2 Peter = 2 Pet, 2 Peter
+1 John = 1 Jn, 1 John
+2 John = 2 Jn, 2 John
+3 John = 3 Jn, 3 John
+Jude = Jude, Jude
+Revelation = Rev, Apoc, Apocalypse, Revelation
+
+[pl]
+Genesis = Rdz, Rodzaju
+Exodus = Wj, Wyjścia
+Leviticus = Kpł, Kapłańska
+Numbers = Lb, Liczb
+Deuteronomy = Pwt, Powtórzonego Prawa
+Joshua = Joz, Jozuego
+Judges = Sdz, Sędziów
+Ruth = Rt, Rut
+1 Samuel = 1 Sm, 1 Samuela
+2 Samuel = 2 Sm, 2 Samuela
+1 Kings = 1 Krl, 1 Królewska
+2 Kings = 2 Krl, 2 Królewska
+1 Chronicles = 1 Krn, 1 Kronik
+2 Chronicles = 2 Krn, 2 Kronik
+Ezra = Ezd, Ezdrasza
+Nehemiah = Ne, Nehemiasza
+Tobit = Tb, Tobiasza
+Judith = Jdt, Judyty
+Esther = Est, Estery
+1 Maccabees = 1 Mch, 1 Machabejska
+2 Maccabees = 2 Mch, 2 Machabejska
+Job = Hi, Hioba
+Psalms = Ps, Psalm, Psalmy
+Proverbs = Prz, Przysłów
+Ecclesiastes = Koh, Koheleta
+Song of Solomon = Pnp, Pieśń nad Pieśniami
+Wisdom = Mdr, Mądrości
+Sirach = Syr, Syracha
+Isaiah = Iz, Izajasza
+Jeremiah = Jr, Jeremiasza
+Lamentations = Lm, Lamentacje
+Baruch = Ba, Barucha
+Ezekiel = Ez, Ezechiela
+Daniel = Dn, Daniela
+Hosea = Oz, Ozeasza
+Joel = Jl, Joela
+Amos = Am, Amosa
+Obadiah = Ab, Abdiasza
+Jonah = Jon, Jonasza
+Micah = Mi, Micheasza
+Nahum = Na, Nahuma
+Habakkuk = Ha, Habakuka
+Zephaniah = So, Sofoniasza
+Haggai = Ag, Aggeusza
+Zechariah = Za, Zachariasza
+Malachi = Ml, Malachiasza
+Matthew = Mt, Mateusza
+Mark = Mk, Marka
+Luke = Łk, Łukasza
+John = J, Jana
+The Acts = Dz, Dzieje Apostolskie
+Romans = Rz, Rzymian
+1 Corinthians = 1 Kor, 1 Koryntian
+2 Corinthians = 2 Kor, 2 Koryntian
+Galatians = Ga, Galatów
+Ephesians = Ef, Efezjan
+Philippians = Flp, Filipian
+Colossians = Kol, Kolosan
+1 Thessalonians = 1 Tes, 1 Tesaloniczan
+2 Thessalonians = 2 Tes, 2 Tesaloniczan
+1 Timothy = 1 Tm, 1 Tymoteusza
+2 Timothy = 2 Tm, 2 Tymoteusza
+Titus = Tt, Tytusa
+Philemon = Flm, Filemona
+Hebrews = Hbr, Hebrajczyków
+James = Jk, Jakuba
+1 Peter = 1 P, 1 Piotra
+2 Peter = 2 P, 2 Piotra
+1 John = 1 J, 1 Jana
+2 John = 2 J, 2 Jana
+3 John = 3 J, 3 Jana
+Jude = Jud, Judy
+Revelation = Ap, Apokalipsa
+
+# Latin (Vulgate) — book names/abbreviations for EF citations and Latin sigla.
+[la]
+Genesis = Gen, Genesis
+Exodus = Ex, Exodus
+Leviticus = Lev, Leviticus
+Numbers = Num, Numeri
+Deuteronomy = Deut, Deuteronomium
+Joshua = Ios, Iosue
+Judges = Idc, Iudicum
+Ruth = Ruth
+1 Samuel = 1 Reg, 1 Sam, 1 Samuelis, 1 Regum
+2 Samuel = 2 Reg, 2 Sam, 2 Samuelis, 2 Regum
+1 Kings = 3 Reg, 3 Regum
+2 Kings = 4 Reg, 4 Regum
+1 Chronicles = 1 Par, 1 Paralipomenon
+2 Chronicles = 2 Par, 2 Paralipomenon
+Ezra = Esd, 1 Esdrae, Esdrae
+Nehemiah = Neh, 2 Esd, Nehemiae
+Tobit = Tob, Tobiae, Tobias
+Judith = Idt, Iudith
+Esther = Esth, Esther
+1 Maccabees = 1 Mac, 1 Machabaeorum
+2 Maccabees = 2 Mac, 2 Machabaeorum
+Job = Iob
+Psalms = Ps, Psalmi
+Proverbs = Prov, Proverbia
+Ecclesiastes = Eccle, Ecclesiastes
+Song of Solomon = Cant, Canticum, Canticum Canticorum
+Wisdom = Sap, Sapientia
+Sirach = Eccli, Ecclus, Sir, Ecclesiasticus
+Isaiah = Is, Isaias
+Jeremiah = Ier, Ieremias
+Lamentations = Lam, Threni, Lamentationes
+Baruch = Bar, Baruch
+Ezekiel = Ez, Ezechiel
+Daniel = Dan, Daniel
+Hosea = Os, Osee
+Joel = Ioel
+Amos = Am, Amos
+Obadiah = Abd, Abdias
+Jonah = Ion, Ionas
+Micah = Mich, Michaeas
+Nahum = Nah, Nahum
+Habakkuk = Hab, Habacuc
+Zephaniah = Soph, Sophonias
+Haggai = Agg, Aggaeus
+Zechariah = Zach, Zacharias
+Malachi = Mal, Malachias
+Matthew = Matt, Matthaeus
+Mark = Marc, Marcus
+Luke = Luc, Lucas
+John = Ioann, Ioannes
+The Acts = Act, Actus, Actus Apostolorum
+Romans = Rom, Romanos
+1 Corinthians = 1 Cor, 1 Corinthios
+2 Corinthians = 2 Cor, 2 Corinthios
+Galatians = Gal, Galatas
+Ephesians = Eph, Ephesios
+Philippians = Phil, Philippenses
+Colossians = Col, Colossenses
+1 Thessalonians = 1 Thess, 1 Thessalonicenses
+2 Thessalonians = 2 Thess, 2 Thessalonicenses
+1 Timothy = 1 Tim, 1 Timotheum
+2 Timothy = 2 Tim, 2 Timotheum
+Titus = Tit, Titum
+Philemon = Philem, Philemonem
+Hebrews = Hebr, Hebraeos
+James = Iac, Iacobi
+1 Peter = 1 Pet, 1 Petri
+2 Peter = 2 Pet, 2 Petri
+1 John = 1 Ioann, 1 Ioannis
+2 John = 2 Ioann, 2 Ioannis
+3 John = 3 Ioann, 3 Ioannis
+Jude = Iud, Iudae
+Revelation = Apoc, Apocalypsis
diff --git a/internal/bible/booktable.go b/internal/bible/booktable.go
index ac7ea95..ae005a5 100644
--- a/internal/bible/booktable.go
+++ b/internal/bible/booktable.go
@@ -6,13 +6,13 @@ import (
 	"sort"
 	"strings"
 
-	"github.com/pelletier/go-toml/v2"
+	"github.com/lukaszkasprzak/lectio/internal/ini"
 )
 
-// booksFS embeds the built-in default book table (names + abbreviations per UI
-// language). Users override it per book via ~/.config/lectio/books.toml.
+// booksFS embeds the built-in default book table (names + abbreviations per
+// dialect: en/pl/la). Users override it per book via ~/.config/lectio/books.ini.
 //
-//go:embed books.toml
+//go:embed books.ini
 var booksFS embed.FS
 
 // BookInfo is one book's display data in one dialect, for `lectio --list` and
@@ -23,8 +23,8 @@ type BookInfo struct {
 	Shortcut  string // primary abbreviation in the dialect, e.g. "Jn" / "J"
 }
 
-// BookTable resolves book references and lists books per "dialect" -- a books.toml
-// section, keyed by the same codes as the UI languages ("en"/"pl"). It is built
+// BookTable resolves book references and lists books per "dialect" -- a books.ini
+// section, keyed by dialect ("en"/"pl"/"la"). It is built
 // from the embedded default merged with an optional user override.
 type BookTable struct {
 	forms   map[string]map[string][]string // dialect -> canonical -> forms (first=shortcut, last=name)
@@ -38,16 +38,16 @@ type BookTable struct {
 // It always returns a usable table; a non-nil error means userTOML was present
 // but unparseable (the returned table is defaults-only, so callers can warn and
 // proceed).
-func LoadBookTable(userTOML []byte) (*BookTable, error) {
+func LoadBookTable(userINI []byte) (*BookTable, error) {
 	def, err := parseBooks(mustReadEmbedded())
 	if err != nil {
-		return nil, fmt.Errorf("embedded books.toml: %w", err) // our bug, not the user's
+		return nil, fmt.Errorf("embedded books.ini: %w", err) // our bug, not the user's
 	}
 	var uerr error
-	if len(strings.TrimSpace(string(userTOML))) > 0 {
-		user, perr := parseBooks(userTOML)
+	if len(strings.TrimSpace(string(userINI))) > 0 {
+		user, perr := parseBooks(userINI)
 		if perr != nil {
-			uerr = fmt.Errorf("ignoring malformed books.toml: %w", perr)
+			uerr = fmt.Errorf("ignoring malformed books.ini: %w", perr)
 		} else {
 			for dialect, books := range user {
 				if def[dialect] == nil {
@@ -84,20 +84,32 @@ func LoadBookTable(userTOML []byte) (*BookTable, error) {
 }
 
 func mustReadEmbedded() []byte {
-	b, _ := booksFS.ReadFile("books.toml") // embedded: always present
+	b, _ := booksFS.ReadFile("books.ini") // embedded: always present
 	return b
 }
 
-// DefaultBooksTOML returns the embedded default books.toml (the seed the
+// DefaultBooksTOML returns the embedded default books.ini (the seed the
 // /settings editor shows when the user has no override yet).
-func DefaultBooksTOML() []byte { return mustReadEmbedded() }
+func DefaultBooksINI() []byte { return mustReadEmbedded() }
 
 func parseBooks(data []byte) (map[string]map[string][]string, error) {
-	var raw map[string]map[string][]string
-	if err := toml.Unmarshal(data, &raw); err != nil {
+	secs, err := ini.Parse(data)
+	if err != nil {
 		return nil, err
 	}
-	return raw, nil
+	out := map[string]map[string][]string{}
+	for _, s := range secs {
+		if s.Name == "" { // no top-level pairs in the book table
+			continue
+		}
+		if out[s.Name] == nil {
+			out[s.Name] = map[string][]string{}
+		}
+		for _, p := range s.Pairs {
+			out[s.Name][p.Key] = ini.List(p.Val)
+		}
+	}
+	return out, nil
 }
 
 // Books returns every book of the dialect in scriptural (canonOrder) order.
diff --git a/internal/bible/booktable_test.go b/internal/bible/booktable_test.go
index 2a57d80..2fdd891 100644
--- a/internal/bible/booktable_test.go
+++ b/internal/bible/booktable_test.go
@@ -97,7 +97,7 @@ func TestFormatRef(t *testing.T) {
 
 func TestBookTableMergeAndMalformed(t *testing.T) {
 	// User adds an alias "Jhn" to English John; other books stay default.
-	user := []byte("[en]\nJohn = [\"Jn\", \"Jhn\", \"John\"]\n")
+	user := []byte("[en]\nJohn = Jn, Jhn, John\n")
 	tbl, err := LoadBookTable(user)
 	if err != nil {
 		t.Fatalf("merge err: %v", err)
@@ -108,12 +108,12 @@ func TestBookTableMergeAndMalformed(t *testing.T) {
 	if got, ok := tbl.ParseRef("en", "Gen 1:1"); !ok || got != "Genesis 1:1" {
 		t.Errorf("unlisted book lost after merge: %q,%v", got, ok)
 	}
-	// Malformed user TOML -> non-nil error but a usable defaults table.
-	tbl2, err := LoadBookTable([]byte("this is not [valid toml"))
+	// Malformed user INI -> non-nil error but a usable defaults table.
+	tbl2, err := LoadBookTable([]byte("this is not valid ini"))
 	if err == nil {
-		t.Error("expected error for malformed user toml")
+		t.Error("expected error for malformed user ini")
 	}
 	if got, ok := tbl2.ParseRef("en", "Jn 3:16"); !ok || got != "John 3:16" {
-		t.Errorf("defaults unusable after malformed user toml: %q,%v", got, ok)
+		t.Errorf("defaults unusable after malformed user ini: %q,%v", got, ok)
 	}
 }
diff --git a/internal/cli/cli.go b/internal/cli/cli.go
index 575fba9..65be274 100644
--- a/internal/cli/cli.go
+++ b/internal/cli/cli.go
@@ -227,7 +227,7 @@ func Run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 	}
 
 	if citation || week || randV || randCh {
-		tbl, _ := bible.LoadBookTable(userBooksTOML())
+		tbl, _ := bible.LoadBookTable(userBooksINI())
 		switch {
 		case randV || randCh:
 			ver, verr := randVersion(cfg, bibleVer)
@@ -300,7 +300,7 @@ func Run(args []string, stdin io.Reader, stdout, stderr io.Writer) int {
 
 	var bookTbl *bible.BookTable
 	if list || ref != "" {
-		tbl, terr := bible.LoadBookTable(userBooksTOML())
+		tbl, terr := bible.LoadBookTable(userBooksINI())
 		if terr != nil {
 			fmt.Fprintln(stderr, "lectio:", terr) // warn; tbl is still a usable defaults table
 		}
@@ -516,17 +516,7 @@ func runWeek(cfg config.Config, tbl *bible.BookTable, date string, refresh bool,
 
 // userBooksTOML returns the bytes of the optional user books.toml, or nil if
 // it is absent/unreadable (built-in defaults are used).
-func userBooksTOML() []byte {
-	p, err := config.BooksPath()
-	if err != nil {
-		return nil
-	}
-	b, err := os.ReadFile(p)
-	if err != nil {
-		return nil
-	}
-	return b
-}
+func userBooksINI() []byte { return config.UserBooksINI() }
 
 // wantsHelp reports whether -h/--help appears anywhere in args.
 func wantsHelp(args []string) bool {
diff --git a/internal/cli/liturgy.go b/internal/cli/liturgy.go
index fc3efae..840e9a6 100644
--- a/internal/cli/liturgy.go
+++ b/internal/cli/liturgy.go
@@ -31,7 +31,7 @@ func runLiturgy(cfg config.Config, date string, stdout, stderr io.Writer) int {
 		fmt.Fprintln(stderr, "lectio: warning:", e)
 	}
 	day := calendar.Compute(d.UTC(), cfg.Selection(), layers)
-	tbl, _ := bible.LoadBookTable(userBooksTOML())
+	tbl, _ := bible.LoadBookTable(userBooksINI())
 	printLiturgicalDay(stdout, cfg, tbl, day)
 	return 0
 }
@@ -45,19 +45,23 @@ func vernacularVersion(cfg config.Config) string {
 	return "drb"
 }
 
-// readingText resolves an English citation and returns its text from version,
-// or "" if it does not resolve.
-func readingText(tbl *bible.BookTable, version, citation string) string {
+// readingLine resolves an English-authored citation and returns (display,
+// text): display is the citation re-formatted in the user's configured sigla
+// dialect (SiglaLang); text is the verses from version (or "" if unresolved).
+// The reading data is authored in English, so it is parsed in the "en" dialect;
+// only the display honors the configured dialect's abbreviations.
+func readingLine(tbl *bible.BookTable, cfg config.Config, version, citation string) (string, string) {
 	engRef, ok := tbl.ParseRef("en", citation)
 	if !ok {
-		return ""
+		return citation, "" // unparseable: show as authored
 	}
+	display := tbl.FormatRef(cfg.SiglaLang(), engRef)
 	vs, _ := bible.Lookup(version, engRef)
 	parts := make([]string, 0, len(vs))
 	for _, v := range vs {
 		parts = append(parts, strings.TrimSpace(v.Text))
 	}
-	return strings.Join(parts, " ")
+	return display, strings.Join(parts, " ")
 }
 
 func printLiturgicalDay(out io.Writer, cfg config.Config, tbl *bible.BookTable, day calendar.LiturgicalDay) {
@@ -81,8 +85,9 @@ func printLiturgicalDay(out io.Writer, cfg config.Config, tbl *bible.BookTable,
 			if m.Variant != "" {
 				label = m.Variant + " " + label
 			}
-			fmt.Fprintf(out, "\n  %s (%s):\n", label, r.Citation)
-			if txt := readingText(tbl, vern, r.Citation); txt != "" {
+			disp, txt := readingLine(tbl, cfg, vern, r.Citation)
+			fmt.Fprintf(out, "\n  %s (%s):\n", label, disp)
+			if txt != "" {
 				for _, line := range strings.Split(render.Wrap(txt, 72), "\n") {
 					fmt.Fprintf(out, "    %s\n", line)
 				}
diff --git a/internal/config/config.go b/internal/config/config.go
index 54185d1..8d2ddca 100644
--- a/internal/config/config.go
+++ b/internal/config/config.go
@@ -38,7 +38,7 @@ const configHeader = `# lectio configuration (INI). Full-line comments only (# o
 #   all               true | false             (all readings, or just the gospel)
 #   offline           true | false             (never fetch; cache/sigla only)
 #   ui_language       en | pl                  (interface chrome; readings stay source-language)
-#   sigla_style       auto | polish | english  (citation dialect; auto follows ui_language)
+#   sigla_style       auto | polish | english | latin  (citation dialect; auto follows ui_language)
 #   web_theme         a theme name (see docs/THEMES.md)
 #   web_port          integer; 0 = try 1099, then any free port
 #   web_display       horizontal | vertical | interlinear
@@ -135,6 +135,8 @@ func NormalizeSiglaStyle(s string) string {
 	switch strings.ToLower(strings.TrimSpace(s)) {
 	case "polish", "pl":
 		return "polish"
+	case "latin", "la":
+		return "latin"
 	case "english", "en":
 		return "english"
 	default:
@@ -190,6 +192,8 @@ func (c Config) SiglaLang() string {
 	switch c.SiglaStyle {
 	case "polish":
 		return "pl"
+	case "latin":
+		return "la"
 	case "english":
 		return "en"
 	default:
@@ -270,7 +274,7 @@ func CalendarsDir() (string, error) {
 	return filepath.Join(filepath.Dir(p), "calendars"), nil
 }
 
-// BooksPath returns the path to the optional user books.toml (in the same
+// BooksPath returns the path to the optional user books.ini (in the same
 // directory as the config file). There is no embedded seed on disk -- absence
 // means "use the built-in defaults".
 func BooksPath() (string, error) {
@@ -278,22 +282,74 @@ func BooksPath() (string, error) {
 	if err != nil {
 		return "", err
 	}
-	return filepath.Join(filepath.Dir(p), "books.toml"), nil
+	return filepath.Join(filepath.Dir(p), "books.ini"), nil
 }
 
-// UserBooksTOML returns the bytes of the optional user books.toml (see
-// BooksPath), or nil when it is absent or unreadable -- callers then fall back
-// to bible's embedded default table.
-func UserBooksTOML() []byte {
+// UserBooksINI returns the bytes of the optional user books.ini (see BooksPath),
+// or nil when absent/unreadable -- callers then fall back to bible's embedded
+// default table. A former books.toml at the same location is converted to
+// books.ini once, on first read (the old file is kept).
+func UserBooksINI() []byte {
 	p, err := BooksPath()
 	if err != nil {
 		return nil
 	}
-	b, err := os.ReadFile(p)
+	if b, err := os.ReadFile(p); err == nil {
+		return b
+	}
+	tomlPath := filepath.Join(filepath.Dir(p), "books.toml")
+	data, err := os.ReadFile(tomlPath)
 	if err != nil {
 		return nil
 	}
-	return b
+	out := booksTOMLtoINI(data)
+	if out == nil {
+		return nil
+	}
+	_ = os.WriteFile(p, out, 0o644)
+	fmt.Fprintf(os.Stderr, "lectio: migrated %s -> books.ini (old file kept)\n", tomlPath)
+	return out
+}
+
+// booksTOMLtoINI converts a former books.toml (dialect -> book -> [forms]) into
+// books.ini. Returns nil if the TOML is unparseable.
+func booksTOMLtoINI(data []byte) []byte {
+	var raw map[string]map[string][]string
+	if err := toml.Unmarshal(data, &raw); err != nil {
+		return nil
+	}
+	var b strings.Builder
+	b.WriteString("# lectio book names & abbreviations, per dialect (migrated from books.toml).\n")
+	emit := func(d string) {
+		books := raw[d]
+		if books == nil {
+			return
+		}
+		fmt.Fprintf(&b, "\n[%s]\n", d)
+		keys := make([]string, 0, len(books))
+		for k := range books {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+		for _, k := range keys {
+			fmt.Fprintf(&b, "%s = %s\n", k, strings.Join(books[k], ", "))
+		}
+	}
+	seen := map[string]bool{"en": true, "pl": true, "la": true}
+	emit("en")
+	emit("pl")
+	emit("la")
+	others := make([]string, 0)
+	for d := range raw {
+		if !seen[d] {
+			others = append(others, d)
+		}
+	}
+	sort.Strings(others)
+	for _, d := range others {
+		emit(d)
+	}
+	return []byte(b.String())
 }
 
 // seedIfMissing writes the embedded default config to path if nothing is
diff --git a/internal/web/server.go b/internal/web/server.go
index a586534..2674802 100644
--- a/internal/web/server.go
+++ b/internal/web/server.go
@@ -62,7 +62,7 @@ func (s *server) apply(cfg config.Config, tbl *bible.BookTable) {
 // query parameters; it is never mutated -- /settings applies changes to a
 // live, mutable copy held by server, which every handler reads per request.
 func NewServer(cfg config.Config) http.Handler {
-	tbl, _ := bible.LoadBookTable(config.UserBooksTOML())
+	tbl, _ := bible.LoadBookTable(config.UserBooksINI())
 	s := &server{cfg: cfg, tbl: tbl, bm: bookmarks.Open()}
 
 	mux := http.NewServeMux()
@@ -719,7 +719,7 @@ func themeCSSHandler(cfg config.Config) http.HandlerFunc {
 // settingsData drives templates/settings.html.
 type settingsData struct {
 	Cfg            config.Config
-	Books          string       // current books.toml text (user override, else the embedded default)
+	Books          string       // current books.ini text (user override, else the embedded default)
 	ThemeOpts      []themeOpt   // for the web_theme <select>
 	VersionOpts    []versionOpt // all five, Checked if in Cfg.Versions
 	WebVersionOpts []versionOpt // all five, Checked if in Cfg.WebVersions
@@ -768,10 +768,10 @@ func newSettingsData(cfg config.Config, books, errMsg string, saved bool) settin
 }
 
 func currentBooksText() string {
-	if b := config.UserBooksTOML(); len(b) > 0 {
+	if b := config.UserBooksINI(); len(b) > 0 {
 		return string(b)
 	}
-	return string(bible.DefaultBooksTOML())
+	return string(bible.DefaultBooksINI())
 }
 
 // settingsGet renders the settings form for the live config.
@@ -785,7 +785,7 @@ func settingsGet(s *server) http.HandlerFunc {
 	}
 }
 
-// settingsPost validates and persists the submitted settings + books.toml, then
+// settingsPost validates and persists the submitted settings + books.ini, then
 // applies them to the running server and redirects (PRG). On a validation error
 // it re-renders the form with the message and the user's edits, HTTP 200.
 func settingsPost(s *server) http.HandlerFunc {
@@ -819,12 +819,12 @@ func settingsPost(s *server) http.HandlerFunc {
 			renderSettingsError(w, cfg, booksText, err.Error())
 			return
 		}
-		// Validate books.toml (parse via the same loader the app uses).
+		// Validate books.ini (parse via the same loader the app uses).
 		var newTbl *bible.BookTable
 		if strings.TrimSpace(booksText) != "" {
 			t, berr := bible.LoadBookTable([]byte(booksText))
 			if berr != nil {
-				renderSettingsError(w, cfg, booksText, "books.toml: "+berr.Error())
+				renderSettingsError(w, cfg, booksText, "books.ini: "+berr.Error())
 				return
 			}
 			newTbl = t
@@ -835,7 +835,7 @@ func settingsPost(s *server) http.HandlerFunc {
 			renderSettingsError(w, cfg, booksText, "saving config: "+err.Error())
 			return
 		}
-		// Only write books.toml when the editor actually carried content, so a
+		// Only write books.ini when the editor actually carried content, so a
 		// submit with an empty/absent books field never clobbers an existing
 		// override (the form always pre-fills the textarea).
 		if strings.TrimSpace(booksText) != "" {
diff --git a/internal/web/server_test.go b/internal/web/server_test.go
index 284a454..12542e5 100644
--- a/internal/web/server_test.go
+++ b/internal/web/server_test.go
@@ -561,19 +561,19 @@ func TestSettingsPostInvalidBooks(t *testing.T) {
 	post.Header.Set("Content-Type", "application/x-www-form-urlencoded")
 	rec := httptest.NewRecorder()
 	srv.ServeHTTP(rec, post)
-	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "books.toml") {
+	if rec.Code != 200 || !strings.Contains(rec.Body.String(), "books.ini") {
 		t.Errorf("invalid books should re-render with an error, got %d", rec.Code)
 	}
 }
 
-func bibleDefaultBooks() []byte { return bible.DefaultBooksTOML() }
+func bibleDefaultBooks() []byte { return bible.DefaultBooksINI() }
 
 // TestSettingsPostEmptyBooksPreservesFile guards that a submit without a books
-// field never clobbers an existing books.toml override.
+// field never clobbers an existing books.ini override.
 func TestSettingsPostEmptyBooksPreservesFile(t *testing.T) {
 	dir := t.TempDir()
 	t.Setenv("LECTIO_CONFIG", filepath.Join(dir, "config.toml"))
-	booksPath := filepath.Join(dir, "books.toml")
+	booksPath := filepath.Join(dir, "books.ini")
 	original := []byte("[en]\nJohn = [\"Jn\", \"John\"]\n")
 	if err := os.WriteFile(booksPath, original, 0o644); err != nil {
 		t.Fatal(err)
@@ -594,7 +594,7 @@ func TestSettingsPostEmptyBooksPreservesFile(t *testing.T) {
 		t.Fatalf("status %d", rec.Code)
 	}
 	if got, _ := os.ReadFile(booksPath); string(got) != string(original) {
-		t.Errorf("empty books submit clobbered books.toml: got %q", got)
+		t.Errorf("empty books submit clobbered books.ini: got %q", got)
 	}
 }
 
diff --git a/internal/web/templates/settings.html b/internal/web/templates/settings.html
index be08e6d..e2ee39e 100644
--- a/internal/web/templates/settings.html
+++ b/internal/web/templates/settings.html
@@ -1,5 +1,5 @@
 {{/* settings.html — lectio-web /settings page: a form for every config
-     setting plus a raw books.toml editor. A plain POST form (no htmx) --
+     setting plus a raw books.ini editor. A plain POST form (no htmx) --
      saving redirects (PRG) back here with ?saved=1. On a validation error
      the form re-renders with the submitted values and an inline message
      instead of redirecting. Self-contained and theme-aware, like index.html. */}}
@@ -100,7 +100,7 @@
       <input type="text" name="pager" value="{{.Cfg.Pager}}">
     </label>
 
-    <label>books.toml
+    <label>books.ini
       <textarea name="books" rows="20">{{.Books}}</textarea>
     </label>