chore: refactoring and tests, splitting up files (#12495)

packages/app/src/pages/session/session-command-helpers.ts

@@ -0,0 +1,10 @@
+export const canAddSelectionContext = (input: {
+  active?: string
+  pathFromTab: (tab: string) => string | undefined
+  selectedLines: (path: string) => unknown
+}) => {
+  if (!input.active) return false
+  const path = input.pathFromTab(input.active)
+  if (!path) return false
+  return input.selectedLines(path) != null
+}