Rename main folders and write sql backend adaptor

frontend/src/stores/recentsStore.js

@@ -0,0 +1,23 @@
+import create from 'zustand'
+import { persist } from 'zustand/middleware'
+
+const useRecentsStore = create(persist(
+  set => ({
+    recents: [],
+
+    addRecent: event => set(state => {
+      const recents = state.recents.filter(e => e.id !== event.id)
+      recents.unshift(event)
+      recents.length = Math.min(recents.length, 5)
+      return { recents }
+    }),
+    removeRecent: id => set(state => {
+      const recents = state.recents.filter(e => e.id !== id)
+      return { recents }
+    }),
+    clearRecents: () => set({ recents: [] }),
+  }),
+  { name: 'crabfit-recent' },
+))
+
+export default useRecentsStore