Add multiselect board filters and letter-jump on picker menus.

Persist comma-separated list filters per project, toggle with space, and jump by first letter in board and project pickers.

Co-authored-by: Cursor <cursoragent@cursor.com>

internal/ui/views/projects.go

@@ -1,6 +1,8 @@
 package views
 
 import (
+	"unicode"
+
 	"github.com/charmbracelet/bubbles/list"
 
 	"task/internal/project"
@@ -46,6 +48,33 @@ func NewProjectList(projects []project.Project, activeID string, width, height i
 	return l
 }
 
+// JumpProjectByLetter cycles to the next project whose name starts with r.
+func JumpProjectByLetter(l *list.Model, r rune) bool {
+	r = unicode.ToLower(r)
+	items := l.Items()
+	n := len(items)
+	if n == 0 {
+		return false
+	}
+	start := l.Index()
+	for step := 1; step <= n; step++ {
+		i := (start + step) % n
+		pi, ok := items[i].(ProjectItem)
+		if !ok {
+			continue
+		}
+		name := []rune(pi.Project.Name)
+		if len(name) == 0 {
+			continue
+		}
+		if unicode.ToLower(name[0]) == r {
+			l.Select(i)
+			return true
+		}
+	}
+	return false
+}
+
 // ProjectsToItems converts projects to list items.
 func ProjectsToItems(projects []project.Project, activeID string) []list.Item {
 	items := make([]list.Item, len(projects))