feat: add navigation and window size handlers with corresponding tests

internal/handlers/keyMsgHandler.go

@@ -0,0 +1,32 @@
+package handlers
+
+import (
+	"github.com/StevanFreeborn/term-tier/internal/core"
+	"github.com/StevanFreeborn/term-tier/internal/state"
+	tea "github.com/charmbracelet/bubbletea"
+)
+
+type KeyMsgHandler interface {
+	KeysHandled() []string
+	Description() string
+	Match(s state.State, msg tea.KeyMsg) bool
+	Handle(s state.State, msg tea.KeyMsg) tea.Cmd
+}
+
+func GetAllKeyHandlers(saver core.Saver) []KeyMsgHandler {
+	return []KeyMsgHandler{
+		NewTextInputHandler(),
+		NewQuitHandler(),
+		NewUpNavigationHandler(),
+		NewDownNavigationHandler(),
+		NewLeftNavigationHandler(),
+		NewRightNavigationHandler(),
+		NewDeleteItemHandler(),
+		NewAddItemHandler(),
+		NewUpdateItemHandler(),
+		NewSelectItemHandler(),
+		NewLoadHandler(saver),
+		NewSaveHandler(saver),
+		NewHelpHandler(),
+	}
+}