feat: complete v0.2 source and sync management

app/admin/page.tsx

@@ -0,0 +1,12 @@
+import { redirect } from "next/navigation";
+import { getSession } from "@/lib/auth";
+import { db } from "@/lib/db";
+
+export const dynamic = "force-dynamic";
+
+export default async function AdminPage() {
+  const user = await getSession(); if (!user || user.role !== "admin") redirect("/");
+  const failures = db.prepare("SELECT j.id,j.kind,j.trigger,j.status,j.attempts,j.last_error,j.created_at,j.finished_at,s.id AS source_id,s.name,s.base_url FROM sync_jobs j JOIN sources s ON s.id=j.source_id WHERE j.status='failed' OR s.sync_status='error' ORDER BY COALESCE(j.finished_at,j.created_at) DESC LIMIT 100").all() as any[];
+  const sources = db.prepare("SELECT s.id,s.name,s.base_url,s.sync_status,s.last_synced_at,s.last_error,s.is_enabled,count(sm.user_id) AS member_count FROM sources s LEFT JOIN source_members sm ON sm.source_id=s.id GROUP BY s.id ORDER BY s.id DESC").all() as any[];
+  return <><h1>管理員：同步狀態</h1><section className="card"><h2>失敗或異常工作</h2>{failures.length ? <ul className="job-list">{failures.map((item) => <li key={`${item.id}-${item.source_id}`}><strong>{item.name}</strong>（來源 #{item.source_id}） · {item.kind || "source"} · <span className="tag">{item.status || "error"}</span><br /><span className="error">{item.last_error || "來源處於錯誤狀態"}</span><br /><span className="meta">嘗試 {item.attempts || 0} 次；{new Date((item.finished_at || item.created_at) + "Z").toLocaleString("zh-TW")}</span></li>)}</ul> : <p className="muted">沒有同步異常。</p>}</section><section className="card"><h2>所有來源</h2><ul className="job-list">{sources.map((source) => <li key={source.id}><strong>{source.name}</strong> · <span className="tag">{source.is_enabled ? source.sync_status : "disabled"}</span> · 成員 {source.member_count}<br /><span className="meta">#{source.id} · {source.base_url} · 上次同步：{source.last_synced_at || "尚未完成"}</span>{source.last_error && <><br /><span className="error">{source.last_error}</span></>}</li>)}</ul></section></>;
+}