feat(frontend): classic skin default + frontend UI rework

frontend/src/app/workspace/scheduled-tasks/new/page.tsx

@@ -0,0 +1,182 @@
+"use client";
+
+import { ArrowLeftIcon, CalendarClock, TriangleAlertIcon } from "lucide-react";
+import { useRouter, useSearchParams } from "next/navigation";
+import { useState } from "react";
+
+import { Alert, AlertDescription, AlertTitle } from "@/components/ui/alert";
+import { Button } from "@/components/ui/button";
+import { Input } from "@/components/ui/input";
+import { Textarea } from "@/components/ui/textarea";
+import {
+  ScheduledTaskScheduleInput,
+  type ScheduleValue,
+} from "@/components/workspace/scheduled-task-schedule-input";
+import { useI18n } from "@/core/i18n/hooks";
+import { useCreateScheduledTask } from "@/core/scheduled-tasks/hooks";
+
+function ReuseThreadNotice({
+  title,
+  description,
+}: {
+  title: string;
+  description: string;
+}) {
+  return (
+    <Alert className="border-amber-500/50 bg-amber-500/10">
+      <TriangleAlertIcon className="text-amber-600 dark:text-amber-400" />
+      <AlertTitle>{title}</AlertTitle>
+      <AlertDescription>{description}</AlertDescription>
+    </Alert>
+  );
+}
+
+export default function NewScheduledTaskPage() {
+  const { t } = useI18n();
+  const router = useRouter();
+  const searchParams = useSearchParams();
+  const initialThreadId = searchParams.get("thread_id");
+  const st = t.scheduledTasks;
+  const createTask = useCreateScheduledTask();
+  const [contextMode, setContextMode] = useState<
+    "fresh_thread_per_run" | "reuse_thread"
+  >(initialThreadId ? "reuse_thread" : "fresh_thread_per_run");
+  const [targetThreadId, setTargetThreadId] = useState(initialThreadId ?? "");
+  const [title, setTitle] = useState("");
+  const [prompt, setPrompt] = useState("");
+  const [createSchedule, setCreateSchedule] = useState<ScheduleValue>({
+    schedule_type: "cron",
+    schedule_spec: { cron: "0 9 * * *" },
+    timezone: "",
+  });
+
+  const listHref = initialThreadId
+    ? `/workspace/scheduled-tasks?thread_id=${encodeURIComponent(initialThreadId)}`
+    : "/workspace/scheduled-tasks";
+
+  const handleCreate = () => {
+    createTask.mutate(
+      {
+        context_mode: contextMode,
+        thread_id: contextMode === "reuse_thread" ? targetThreadId : null,
+        title,
+        prompt,
+        schedule_type: createSchedule.schedule_type,
+        schedule_spec: createSchedule.schedule_spec,
+        timezone: createSchedule.timezone || "UTC",
+      },
+      { onSuccess: () => router.push(listHref) },
+    );
+  };
+
+  return (
+    <div className="flex size-full flex-col">
+      <header className="flex shrink-0 items-center justify-between gap-3 border-b px-4 py-3">
+        <div className="flex items-center gap-3">
+          <Button
+            variant="ghost"
+            size="icon-sm"
+            aria-label={st.create.back}
+            title={st.create.back}
+            onClick={() => router.push(listHref)}
+          >
+            <ArrowLeftIcon className="h-4 w-4" />
+          </Button>
+          <h1 className="text-sm font-semibold">{st.create.title}</h1>
+        </div>
+      </header>
+      <main className="flex flex-1 justify-center overflow-y-auto px-4 py-6">
+        <div
+          className="my-auto w-full max-w-xl space-y-4"
+          data-testid="scheduled-task-create-form"
+        >
+          <div className="space-y-3 pb-2 text-center">
+            <div className="bg-primary/10 mx-auto flex h-14 w-14 items-center justify-center rounded-full">
+              <CalendarClock className="text-primary h-7 w-7" />
+            </div>
+            <div className="space-y-1">
+              <h2 className="text-xl font-semibold">{st.create.title}</h2>
+              <p className="text-muted-foreground text-sm">{st.description}</p>
+            </div>
+          </div>
+          <div className="flex flex-wrap gap-2">
+            <Button
+              type="button"
+              variant={
+                contextMode === "fresh_thread_per_run" ? "default" : "outline"
+              }
+              size="sm"
+              onClick={() => setContextMode("fresh_thread_per_run")}
+            >
+              {st.context.fresh}
+            </Button>
+            <Button
+              type="button"
+              variant={contextMode === "reuse_thread" ? "default" : "outline"}
+              size="sm"
+              onClick={() => setContextMode("reuse_thread")}
+            >
+              {st.context.reuse}
+            </Button>
+          </div>
+          {contextMode === "reuse_thread" && (
+            <>
+              <Input
+                value={targetThreadId}
+                onChange={(event) => setTargetThreadId(event.target.value)}
+                placeholder={st.context.threadIdPlaceholder}
+              />
+              <ReuseThreadNotice
+                title={st.context.reuseNoticeTitle}
+                description={st.context.reuseNoticeDescription}
+              />
+            </>
+          )}
+          <Input
+            value={title}
+            onChange={(event) => setTitle(event.target.value)}
+            placeholder={st.create.taskTitle}
+          />
+          <Textarea
+            rows={4}
+            value={prompt}
+            onChange={(event) => setPrompt(event.target.value)}
+            placeholder={st.create.prompt}
+          />
+          <ScheduledTaskScheduleInput
+            initial={createSchedule}
+            onChange={setCreateSchedule}
+          />
+          {createSchedule.schedule_type === "once" &&
+            !createSchedule.schedule_spec.run_at && (
+              <div className="text-muted-foreground text-sm">
+                {st.create.invalidOnce}
+              </div>
+            )}
+          <div className="flex justify-end gap-2">
+            <Button
+              variant="outline"
+              onClick={() => router.push(listHref)}
+              disabled={createTask.isPending}
+            >
+              {t.common.cancel}
+            </Button>
+            <Button
+              onClick={handleCreate}
+              disabled={
+                !title ||
+                !prompt ||
+                (!createSchedule.schedule_spec.cron &&
+                  !createSchedule.schedule_spec.run_at) ||
+                (contextMode === "reuse_thread" && !targetThreadId) ||
+                createTask.isPending
+              }
+            >
+              {createTask.isPending ? t.common.loading : st.create.submit}
+            </Button>
+          </div>
+        </div>
+      </main>
+    </div>
+  );
+}