fix(tui): harden EDITOR handling and SQL sort/order validation

Split EDITOR env var on whitespace so multi-word values like
"code --wait" work correctly. Add allow-list switch for sort column
and order direction at the query boundary to prevent future callers
from passing unsanitized values into SQL.

internal/db/entities.go

@@ -220,12 +220,20 @@ func (s *Store) List(params ListParams) ([]*Entity, error) {
 	}
 
 	orderCol := "e.created_at"
-	if params.Sort == "use_count" {
+	switch params.Sort {
+	case "use_count":
 		orderCol = "e.use_count"
+	case "created_at", "":
+		orderCol = "e.created_at"
+	default:
+		orderCol = "e.created_at"
 	}
 	orderDir := "DESC"
-	if strings.EqualFold(params.Order, "asc") {
+	switch strings.ToLower(params.Order) {
+	case "asc":
 		orderDir = "ASC"
+	default:
+		orderDir = "DESC"
 	}
 
 	limit := params.Limit

internal/tui/commands.go

@@ -3,6 +3,7 @@ package tui
 import (
 	"os"
 	"os/exec"
+	"strings"
 	"time"
 
 	"github.com/atotto/clipboard"
@@ -179,10 +180,12 @@ func loadTags(store *db.Store) tea.Cmd {
 }
 
 func editInEditor(store *db.Store, e *db.Entity) tea.Cmd {
-	editor := os.Getenv("EDITOR")
+	editorEnv := os.Getenv("EDITOR")
-	if editor == "" {
+	if editorEnv == "" {
-		editor = "vi"
+		editorEnv = "vi"
 	}
+	parts := strings.Fields(editorEnv)
+	editor, editorArgs := parts[0], parts[1:]
 
 	f, err := os.CreateTemp("", "nib-edit-*.md")
 	if err != nil {
@@ -195,7 +198,7 @@ func editInEditor(store *db.Store, e *db.Entity) tea.Cmd {
 	}
 	f.Close()
 
-	c := exec.Command(editor, f.Name())
+	c := exec.Command(editor, append(editorArgs, f.Name())...)
 	return tea.ExecProcess(c, func(err error) tea.Msg {
 		defer os.Remove(f.Name())
 		if err != nil {