feat: Sprint 4 complete — frontend MVP (admin dashboard + member portal)

Shadboard starter-kit (Next.js 15 + React 19 + shadcn/ui + Tailwind 4)

Sprint 4.a — Admin Dashboard:
- Auth: NextAuth.js v5, login page, middleware, token rotation
- Dashboard: KPI cards, Recharts stock chart, quick actions
- Members: TanStack Table (search/sort/paginate), add/edit forms
- Distributions: multi-step form, real-time quota check, history
- Stock: batch management, recall dialog, bar chart
- Reports: monthly/member-list/recall, PDF/CSV download, preview

Sprint 4.b — Member Portal:
- Separate route group with top-nav layout (mobile-first)
- Quota dashboard with radial SVG progress indicators
- Distribution history with month filter
- Profile/settings with password change

Cross-cutting:
- i18n: German (default) + English via next-intl
- Dark + light mode (next-themes, user-togglable)
- Playwright E2E tests (6/6 green)
- Docker multi-stage build (node:22-alpine)
- API proxy via Next.js rewrites

Tech: Next.js 15.2.8, React 19, Tailwind 4, NextAuth v5,
TanStack Table, Recharts, Zod, React Hook Form, Playwright

cannamanage-frontend/src/hooks/use-toast.ts

@@ -0,0 +1,190 @@
+"use client"
+
+// Inspired by react-hot-toast library
+import { useEffect, useState } from "react"
+
+import type { ToastActionElement, ToastProps } from "@/components/ui/toast"
+import type { ReactNode } from "react"
+
+const TOAST_LIMIT = 1
+const TOAST_REMOVE_DELAY = 1000000
+
+type ToasterToast = ToastProps & {
+  id: string
+  title?: ReactNode
+  description?: ReactNode
+  action?: ToastActionElement
+}
+
+let count = 0
+
+function genId() {
+  count = (count + 1) % Number.MAX_SAFE_INTEGER
+  return count.toString()
+}
+
+type ActionType = {
+  ADD_TOAST: "ADD_TOAST"
+  UPDATE_TOAST: "UPDATE_TOAST"
+  DISMISS_TOAST: "DISMISS_TOAST"
+  REMOVE_TOAST: "REMOVE_TOAST"
+}
+
+type Action =
+  | {
+      type: ActionType["ADD_TOAST"]
+      toast: ToasterToast
+    }
+  | {
+      type: ActionType["UPDATE_TOAST"]
+      toast: Partial<ToasterToast>
+    }
+  | {
+      type: ActionType["DISMISS_TOAST"]
+      toastId?: ToasterToast["id"]
+    }
+  | {
+      type: ActionType["REMOVE_TOAST"]
+      toastId?: ToasterToast["id"]
+    }
+
+interface State {
+  toasts: ToasterToast[]
+}
+
+const toastTimeouts = new Map<string, ReturnType<typeof setTimeout>>()
+
+const addToRemoveQueue = (toastId: string) => {
+  if (toastTimeouts.has(toastId)) {
+    return
+  }
+
+  const timeout = setTimeout(() => {
+    toastTimeouts.delete(toastId)
+    dispatch({
+      type: "REMOVE_TOAST",
+      toastId: toastId,
+    })
+  }, TOAST_REMOVE_DELAY)
+
+  toastTimeouts.set(toastId, timeout)
+}
+
+export const reducer = (state: State, action: Action): State => {
+  switch (action.type) {
+    case "ADD_TOAST":
+      return {
+        ...state,
+        toasts: [action.toast, ...state.toasts].slice(0, TOAST_LIMIT),
+      }
+
+    case "UPDATE_TOAST":
+      return {
+        ...state,
+        toasts: state.toasts.map((t) =>
+          t.id === action.toast.id ? { ...t, ...action.toast } : t
+        ),
+      }
+
+    case "DISMISS_TOAST": {
+      const { toastId } = action
+
+      // ! Side effects ! - This could be extracted into a dismissToast() action,
+      // but I'll keep it here for simplicity
+      if (toastId) {
+        addToRemoveQueue(toastId)
+      } else {
+        state.toasts.forEach((toast) => {
+          addToRemoveQueue(toast.id)
+        })
+      }
+
+      return {
+        ...state,
+        toasts: state.toasts.map((t) =>
+          t.id === toastId || toastId === undefined
+            ? {
+                ...t,
+                open: false,
+              }
+            : t
+        ),
+      }
+    }
+    case "REMOVE_TOAST":
+      if (action.toastId === undefined) {
+        return {
+          ...state,
+          toasts: [],
+        }
+      }
+      return {
+        ...state,
+        toasts: state.toasts.filter((t) => t.id !== action.toastId),
+      }
+  }
+}
+
+const listeners: Array<(state: State) => void> = []
+
+let memoryState: State = { toasts: [] }
+
+function dispatch(action: Action) {
+  memoryState = reducer(memoryState, action)
+  listeners.forEach((listener) => {
+    listener(memoryState)
+  })
+}
+
+type Toast = Omit<ToasterToast, "id">
+
+function toast({ ...props }: Toast) {
+  const id = genId()
+
+  const update = (props: ToasterToast) =>
+    dispatch({
+      type: "UPDATE_TOAST",
+      toast: { ...props, id },
+    })
+  const dismiss = () => dispatch({ type: "DISMISS_TOAST", toastId: id })
+
+  dispatch({
+    type: "ADD_TOAST",
+    toast: {
+      ...props,
+      id,
+      open: true,
+      onOpenChange: (open) => {
+        if (!open) dismiss()
+      },
+    },
+  })
+
+  return {
+    id: id,
+    dismiss,
+    update,
+  }
+}
+
+function useToast() {
+  const [state, setState] = useState<State>(memoryState)
+
+  useEffect(() => {
+    listeners.push(setState)
+    return () => {
+      const index = listeners.indexOf(setState)
+      if (index > -1) {
+        listeners.splice(index, 1)
+      }
+    }
+  }, [state])
+
+  return {
+    ...state,
+    toast,
+    dismiss: (toastId?: string) => dispatch({ type: "DISMISS_TOAST", toastId }),
+  }
+}
+
+export { useToast, toast }