tui(reader): filter bookmarks by tag, and show tags in the list

Bookmarks stored tags but the list neither showed them nor let you use them.
Now each row shows "Ref — note  #tag1 #tag2", and `/` opens a live tag filter
(case-insensitive substring over a bookmark's tags): type to narrow, Enter keeps
the filter while j/k navigate the filtered list, Esc clears it. Navigation,
open and delete all act on the visible (filtered) list. Reuses the store's
existing tag data; help keybar (en/pl) updated; test covers filter/keys.

5 files changed, 157 insertions, 45 deletions

diff --git a/internal/i18n/golden_test.go b/internal/i18n/golden_test.go
index e6dc00a..0dc87dd 100644
--- a/internal/i18n/golden_test.go
+++ b/internal/i18n/golden_test.go
@@ -36,7 +36,7 @@ var enUI = UI{
 	ReaderNoMatch:         "(no matching books)",
 	ReaderMarkPrompt:      "note (enter to save, esc to cancel)",
 	ReaderBookmarksTitle:  "bookmarks",
-	ReaderBookmarksKeys:   "j/k move  enter open  d delete  esc back  q quit",
+	ReaderBookmarksKeys:   "j/k move  enter open  d delete  / tag  esc back  q quit",
 	ReaderNoBookmarks:     "no bookmarks yet — press m while reading",
 	ReaderMarkVerseKeys:   "↑/↓ pick verse  enter add note  esc cancel",
 	ReaderConfirmDelete:   "Delete this bookmark?",
@@ -122,7 +122,7 @@ var plUI = UI{
 	ReaderNoMatch:         "(brak pasujących ksiąg)",
 	ReaderMarkPrompt:      "notatka (enter zapisz, esc anuluj)",
 	ReaderBookmarksTitle:  "zakładki",
-	ReaderBookmarksKeys:   "j/k ruch  enter otwórz  d usuń  esc wróć  q wyjście",
+	ReaderBookmarksKeys:   "j/k ruch  enter otwórz  d usuń  / tag  esc wróć  q wyjście",
 	ReaderNoBookmarks:     "brak zakładek — naciśnij m podczas czytania",
 	ReaderMarkVerseKeys:   "↑/↓ wybierz werset  enter notatka  esc anuluj",
 	ReaderConfirmDelete:   "Usunąć zakładkę?",
diff --git a/internal/i18n/lang/en.ini b/internal/i18n/lang/en.ini
index 4f2d023..87face3 100644
--- a/internal/i18n/lang/en.ini
+++ b/internal/i18n/lang/en.ini
@@ -20,7 +20,7 @@ reader_no_text = (no text in this version)
 reader_no_match = (no matching books)
 reader_mark_prompt = note (enter to save, esc to cancel)
 reader_bookmarks_title = bookmarks
-reader_bookmarks_keys = j/k move  enter open  d delete  esc back  q quit
+reader_bookmarks_keys = j/k move  enter open  d delete  / tag  esc back  q quit
 reader_no_bookmarks = no bookmarks yet — press m while reading
 reader_mark_verse_keys = ↑/↓ pick verse  enter add note  esc cancel
 reader_confirm_delete = Delete this bookmark?
diff --git a/internal/i18n/lang/pl.ini b/internal/i18n/lang/pl.ini
index 1a202dd..cce1854 100644
--- a/internal/i18n/lang/pl.ini
+++ b/internal/i18n/lang/pl.ini
@@ -20,7 +20,7 @@ reader_no_text = (brak tekstu w tej wersji)
 reader_no_match = (brak pasujących ksiąg)
 reader_mark_prompt = notatka (enter zapisz, esc anuluj)
 reader_bookmarks_title = zakładki
-reader_bookmarks_keys = j/k ruch  enter otwórz  d usuń  esc wróć  q wyjście
+reader_bookmarks_keys = j/k ruch  enter otwórz  d usuń  / tag  esc wróć  q wyjście
 reader_no_bookmarks = brak zakładek — naciśnij m podczas czytania
 reader_mark_verse_keys = ↑/↓ wybierz werset  enter notatka  esc anuluj
 reader_confirm_delete = Usunąć zakładkę?
diff --git a/internal/tui/reader.go b/internal/tui/reader.go
index dc9141a..de89a40 100644
--- a/internal/tui/reader.go
+++ b/internal/tui/reader.go
@@ -86,9 +86,11 @@ type ReaderModel struct {
 	markNote      string               // note being typed in modeMark
 	markTags      string               // tags being typed in modeMark
 	markField     int                  // 0 = note field, 1 = tags field
-	marks         []bookmarks.Bookmark // loaded list for modeBookmarks
-	markSel       int                  // selection in the bookmarks list
+	marks         []bookmarks.Bookmark // loaded list for modeBookmarks (unfiltered)
+	markSel       int                  // selection into the VISIBLE (filtered) list
 	markTop       int                  // list scroll offset
+	markFilter    string               // active tag filter (substring, case-insensitive)
+	markFiltering bool                 // typing into the tag filter
 	confirmDelete bool                 // bookmarks list is awaiting delete confirmation
 	flash         string               // transient status line (e.g. "bookmarked ...")
 
@@ -297,6 +299,8 @@ func (m ReaderModel) updateRead(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 		}
 		m.markSel = 0
 		m.markTop = 0
+		m.markFilter = ""
+		m.markFiltering = false
 		m.mode = modeBookmarks
 		return m, nil
 	case "tab":
@@ -407,19 +411,41 @@ func (m ReaderModel) updateMark(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 	return m, nil
 }
 
+// visMarks is the bookmarks currently shown: all of them, or, when a tag filter
+// is set, those with a tag containing it (case-insensitive substring). markSel
+// indexes into this, so navigation/open/delete all act on the visible list.
+func (m ReaderModel) visMarks() []bookmarks.Bookmark {
+	if m.markFilter == "" {
+		return m.marks
+	}
+	q := strings.ToLower(m.markFilter)
+	var out []bookmarks.Bookmark
+	for _, bm := range m.marks {
+		for _, t := range bm.Tags {
+			if strings.Contains(strings.ToLower(t), q) {
+				out = append(out, bm)
+				break
+			}
+		}
+	}
+	return out
+}
+
 // updateBookmarks handles the saved-bookmarks list: navigate, open (jump to that
-// book+chapter+verse), delete, or go back.
+// book+chapter+verse), delete, filter by tag (/), or go back.
 func (m ReaderModel) updateBookmarks(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	vis := m.visMarks()
+
 	if m.confirmDelete {
 		switch msg.String() {
 		case "y":
-			if m.markSel < len(m.marks) && m.store != nil {
-				_ = m.store.Delete(m.marks[m.markSel].ID)
+			if m.markSel < len(vis) && m.store != nil {
+				_ = m.store.Delete(vis[m.markSel].ID)
 				if marks, err := m.store.List(""); err == nil {
 					m.marks = marks
 				}
-				if m.markSel >= len(m.marks) {
-					m.markSel = len(m.marks) - 1
+				if v := m.visMarks(); m.markSel >= len(v) {
+					m.markSel = len(v) - 1
 				}
 				if m.markSel < 0 {
 					m.markSel = 0
@@ -431,15 +457,43 @@ func (m ReaderModel) updateBookmarks(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 		}
 		return m, nil
 	}
+
+	// Tag-filter input: type to narrow live, Enter keeps it (then j/k navigate
+	// the filtered list), Esc clears it.
+	if m.markFiltering {
+		switch msg.Type {
+		case tea.KeyEnter:
+			m.markFiltering = false
+		case tea.KeyEsc:
+			m.markFiltering, m.markFilter, m.markSel = false, "", 0
+		case tea.KeyBackspace:
+			if r := []rune(m.markFilter); len(r) > 0 {
+				m.markFilter, m.markSel = string(r[:len(r)-1]), 0
+			}
+		case tea.KeySpace:
+			m.markFilter, m.markSel = m.markFilter+" ", 0
+		case tea.KeyRunes:
+			m.markFilter, m.markSel = m.markFilter+string(msg.Runes), 0
+		}
+		return m, nil
+	}
+
 	switch msg.String() {
 	case "q", "ctrl+c":
 		m.savePlace()
 		return m, tea.Quit
 	case "esc", "b":
+		if m.markFilter != "" { // first esc clears an active filter, then back
+			m.markFilter, m.markSel = "", 0
+			return m, nil
+		}
 		m.mode = modeRead
 		return m, nil
+	case "/":
+		m.markFiltering = true
+		return m, nil
 	case "j", "down":
-		if m.markSel < len(m.marks)-1 {
+		if m.markSel < len(vis)-1 {
 			m.markSel++
 		}
 		return m, nil
@@ -449,13 +503,13 @@ func (m ReaderModel) updateBookmarks(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 		}
 		return m, nil
 	case "d":
-		if len(m.marks) > 0 {
+		if len(vis) > 0 {
 			m.confirmDelete = true
 		}
 		return m, nil
 	case "enter":
-		if m.markSel < len(m.marks) {
-			bm := m.marks[m.markSel]
+		if m.markSel < len(vis) {
+			bm := vis[m.markSel]
 			if idx := m.bookIndex(bm.Book); idx >= 0 {
 				m.bookIdx = idx
 				m = m.openAt(bm.Chapter, bm.Verse)
@@ -919,37 +973,58 @@ func hardWrap(s string, width int) []string {
 	return lines
 }
 
-// viewBookmarks renders the saved-bookmarks list.
+// markLine renders one bookmark as "Book Chap:Verse — note  #tag1 #tag2"
+// (note and tags shown only when present).
+func (m ReaderModel) markLine(bm bookmarks.Bookmark) string {
+	name := bm.Book
+	if idx := m.bookIndex(bm.Book); idx >= 0 {
+		name = m.books[idx].Name
+	}
+	s := fmt.Sprintf("%s %d", name, bm.Chapter)
+	if bm.Verse > 0 {
+		s += fmt.Sprintf(":%d", bm.Verse)
+	}
+	if bm.Note != "" {
+		s += "  — " + bm.Note
+	}
+	if len(bm.Tags) > 0 {
+		s += "  #" + strings.Join(bm.Tags, " #")
+	}
+	return s
+}
+
+// viewBookmarks renders the saved-bookmarks list (with the tag filter, if any).
 func (m ReaderModel) viewBookmarks() string {
 	w := m.width
 	if w <= 0 {
 		w = 80
 	}
 	ui := i18n.Get(m.cfg.UILanguage)
+	vis := m.visMarks()
 
 	// Deleting -> a prominent centered confirmation dialog naming the bookmark.
-	if m.confirmDelete && m.markSel >= 0 && m.markSel < len(m.marks) {
-		bm := m.marks[m.markSel]
-		name := bm.Book
-		if idx := m.bookIndex(bm.Book); idx >= 0 {
-			name = m.books[idx].Name
-		}
-		ref := fmt.Sprintf("%s %d", name, bm.Chapter)
-		if bm.Verse > 0 {
-			ref += fmt.Sprintf(":%d", bm.Verse)
-		}
-		if bm.Note != "" {
-			ref += "  — " + bm.Note
-		}
-		inner := modalTitleStyle.Render(ui.ReaderConfirmDelete) + "\n\n  " + ref + "\n\n" + citationStyle.Render(ui.ReaderConfirmKeys)
+	if m.confirmDelete && m.markSel >= 0 && m.markSel < len(vis) {
+		inner := modalTitleStyle.Render(ui.ReaderConfirmDelete) + "\n\n  " + m.markLine(vis[m.markSel]) + "\n\n" + citationStyle.Render(ui.ReaderConfirmKeys)
 		return m.modal(inner)
 	}
 
-	header := headerStyle.Width(w).Render(ui.ReaderBookmarksTitle)
+	title := ui.ReaderBookmarksTitle
+	if m.markFilter != "" || m.markFiltering {
+		cursor := ""
+		if m.markFiltering {
+			cursor = "_"
+		}
+		title += "  /" + m.markFilter + cursor
+	}
+	header := headerStyle.Width(w).Render(title)
 	footer := footerStyle.Width(w).Render(ui.ReaderBookmarksKeys)
+
 	if len(m.marks) == 0 {
 		return header + "\n" + citationStyle.Render(ui.ReaderNoBookmarks) + "\n" + footer
 	}
+	if len(vis) == 0 { // a tag filter that matches nothing -- the header shows it
+		return header + "\n" + footer
+	}
 
 	visible := m.height - 3
 	if visible < 3 {
@@ -961,20 +1036,8 @@ func (m ReaderModel) viewBookmarks() string {
 	}
 
 	var rows []string
-	for i := top; i < len(m.marks) && i < top+visible; i++ {
-		bm := m.marks[i]
-		name := bm.Book
-		if idx := m.bookIndex(bm.Book); idx >= 0 {
-			name = m.books[idx].Name
-		}
-		ref := fmt.Sprintf("%s %d", name, bm.Chapter)
-		if bm.Verse > 0 {
-			ref += fmt.Sprintf(":%d", bm.Verse)
-		}
-		row := ref
-		if bm.Note != "" {
-			row += "  — " + bm.Note
-		}
+	for i := top; i < len(vis) && i < top+visible; i++ {
+		row := m.markLine(vis[i])
 		if i == m.markSel {
 			row = selStyle.Render("› " + row)
 		} else {
diff --git a/internal/tui/reader_test.go b/internal/tui/reader_test.go
index 7bce759..da8d4d4 100644
--- a/internal/tui/reader_test.go
+++ b/internal/tui/reader_test.go
@@ -49,6 +49,55 @@ func win(m ReaderModel, w, h int) ReaderModel {
 	return nm.(ReaderModel)
 }
 
+func TestReaderBookmarkTagFilter(t *testing.T) {
+	m := enReader(t)
+	m.marks = []bookmarks.Bookmark{
+		{ID: "1", Book: "John", Chapter: 3, Verse: 16, Tags: []string{"faith"}},
+		{ID: "2", Book: "Psalms", Chapter: 23, Verse: 1, Tags: []string{"work", "prayer"}},
+		{ID: "3", Book: "Matthew", Chapter: 5, Verse: 3, Tags: []string{"prayer"}},
+	}
+	m.mode = modeBookmarks
+
+	if got := len(m.visMarks()); got != 3 {
+		t.Fatalf("unfiltered visible = %d, want 3", got)
+	}
+
+	// "/" enters filter input; typing narrows to the two 'prayer' bookmarks.
+	m = key(m, runes("/"))
+	if !m.markFiltering {
+		t.Fatal(`"/" did not enter filter input`)
+	}
+	for _, c := range []string{"p", "r", "a", "y"} {
+		m = key(m, runes(c))
+	}
+	if got := len(m.visMarks()); got != 2 {
+		t.Fatalf(`filter "pray" visible = %d, want 2 (Psalms, Matthew)`, got)
+	}
+
+	// Enter keeps the filter and leaves input mode.
+	m = key(m, tea.KeyMsg{Type: tea.KeyEnter})
+	if m.markFiltering || m.markFilter != "pray" {
+		t.Fatalf("after enter: filtering=%v filter=%q", m.markFiltering, m.markFilter)
+	}
+
+	// Case-insensitive substring: "WORK" matches the 'work' tag (1 bookmark).
+	m.markFilter = "WORK"
+	if got := len(m.visMarks()); got != 1 {
+		t.Fatalf(`filter "WORK" visible = %d, want 1`, got)
+	}
+
+	// Esc clears an active filter, back to all.
+	m.markFilter = "work"
+	m.markFiltering = false
+	m = key(m, tea.KeyMsg{Type: tea.KeyEsc})
+	if m.markFilter != "" {
+		t.Fatalf("esc did not clear filter, got %q", m.markFilter)
+	}
+	if got := len(m.visMarks()); got != 3 {
+		t.Fatalf("after clearing filter, visible = %d, want 3", got)
+	}
+}
+
 func TestReaderInit(t *testing.T) {
 	m := enReader(t)
 	if m.mode != modePick {