feat: bootstrap MediaStationGo (Go + React rewrite of MediaStation)

Adopt the cropflre/nowen-video tech stack and rebuild the project from
scratch:

  - Backend: Go 1.25 + Gin + GORM + SQLite (WAL) + JWT + WebSocket hub.
    Layered packages config / database / model / repository / service /
    middleware / handler. Default admin (admin/admin123) seeded on first
    run; /api routes for auth, libraries, media, stream and admin
    panels. WebSocket scan-progress events at /api/ws.
  - Frontend: React 18 + Vite 5 + Tailwind 3.4 + Zustand + axios +
    react-router 6 + lucide-react + framer-motion + hls.js. Pages for
    Login / Home / Library / Search / MediaDetail / Player / Admin
    (Library, Users, Settings tabs).
  - Distribution: multi-arch Dockerfile (frontend -> backend -> Alpine
    runtime), docker-compose.yml, GitHub Actions for CI and GHCR
    publish, Makefile, env-prefixed config (MEDIASTATION_*).
  - Docs: README, CONTRIBUTING, .env.example, config.example.yaml.

Backend builds, vets and tests pass. Frontend builds via tsc -b && vite
build (250 kB JS / 16 kB CSS, gzipped 84 / 4 kB).

web/src/pages/AdminPage.tsx

@@ -0,0 +1,253 @@
+import { FormEvent, useEffect, useState } from 'react'
+import toast from 'react-hot-toast'
+import { Trash2 } from 'lucide-react'
+
+import { adminAPI } from '../api/admin'
+import { libraryAPI } from '../api/library'
+import type { Library, User } from '../types'
+
+// Single-page admin console. We split the surface into three panels:
+//   • Libraries  — create / delete / scan
+//   • Users      — list / delete (cannot delete self)
+//   • Settings   — generic key/value store viewer
+//
+// Each panel manages its own loading / refresh state.
+export function AdminPage() {
+  const [tab, setTab] = useState<'library' | 'users' | 'settings'>('library')
+  return (
+    <div className="space-y-6">
+      <h1 className="font-display text-3xl font-bold text-white">管理后台</h1>
+      <div className="flex gap-2 border-b border-white/10">
+        {(['library', 'users', 'settings'] as const).map((k) => (
+          <button
+            key={k}
+            onClick={() => setTab(k)}
+            className={
+              'border-b-2 px-4 py-2 text-sm transition ' +
+              (tab === k
+                ? 'border-primary-400 text-primary-400'
+                : 'border-transparent text-slate-400 hover:text-white')
+            }
+          >
+            {k === 'library' ? '媒体库' : k === 'users' ? '用户' : '设置'}
+          </button>
+        ))}
+      </div>
+
+      {tab === 'library' && <LibraryPanel />}
+      {tab === 'users' && <UsersPanel />}
+      {tab === 'settings' && <SettingsPanel />}
+    </div>
+  )
+}
+
+function LibraryPanel() {
+  const [libs, setLibs] = useState<Library[]>([])
+  const [name, setName] = useState('')
+  const [path, setPath] = useState('')
+  const [type, setType] = useState('movie')
+
+  const refresh = () => libraryAPI.list().then(setLibs)
+  useEffect(() => {
+    refresh().catch(() => undefined)
+  }, [])
+
+  const handleCreate = async (e: FormEvent) => {
+    e.preventDefault()
+    try {
+      await libraryAPI.create(name, path, type)
+      toast.success('媒体库已创建')
+      setName('')
+      setPath('')
+      await refresh()
+    } catch (err: unknown) {
+      const msg =
+        (err as { response?: { data?: { error?: string } } })?.response?.data?.error ??
+        '创建失败'
+      toast.error(msg)
+    }
+  }
+
+  return (
+    <div className="space-y-6">
+      <form onSubmit={handleCreate} className="glass-panel grid gap-3 md:grid-cols-4">
+        <input
+          required
+          className="input-base"
+          placeholder="名称"
+          value={name}
+          onChange={(e) => setName(e.target.value)}
+        />
+        <input
+          required
+          className="input-base md:col-span-2"
+          placeholder="服务器路径,如 /media/movies"
+          value={path}
+          onChange={(e) => setPath(e.target.value)}
+        />
+        <select className="input-base" value={type} onChange={(e) => setType(e.target.value)}>
+          <option value="movie">电影</option>
+          <option value="tv">电视剧</option>
+          <option value="anime">动漫</option>
+          <option value="music">音乐</option>
+        </select>
+        <button type="submit" className="neon-button md:col-span-4">
+          新建媒体库
+        </button>
+      </form>
+
+      <div className="glass-panel">
+        <table className="w-full text-left text-sm">
+          <thead className="text-xs uppercase tracking-wider text-slate-500">
+            <tr>
+              <th className="py-2">名称</th>
+              <th>路径</th>
+              <th>类型</th>
+              <th className="text-right">操作</th>
+            </tr>
+          </thead>
+          <tbody>
+            {libs.map((l) => (
+              <tr key={l.id} className="border-t border-white/5">
+                <td className="py-2 text-white">{l.name}</td>
+                <td className="text-slate-300">{l.path}</td>
+                <td className="text-slate-300">{l.type}</td>
+                <td className="space-x-2 py-2 text-right">
+                  <button
+                    className="rounded border border-primary-400/40 px-2 py-1 text-xs text-primary-400 hover:bg-primary-400/10"
+                    onClick={async () => {
+                      const r = await libraryAPI.scan(l.id)
+                      toast.success(`扫描完成,新增 ${r.added}`)
+                    }}
+                  >
+                    扫描
+                  </button>
+                  <button
+                    className="rounded border border-red-400/40 px-2 py-1 text-xs text-red-400 hover:bg-red-400/10"
+                    onClick={async () => {
+                      if (!confirm(`确定删除「${l.name}」?`)) return
+                      await libraryAPI.remove(l.id)
+                      toast.success('已删除')
+                      await refresh()
+                    }}
+                  >
+                    <Trash2 size={12} />
+                  </button>
+                </td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+      </div>
+    </div>
+  )
+}
+
+function UsersPanel() {
+  const [users, setUsers] = useState<User[]>([])
+  const refresh = () => adminAPI.listUsers().then(setUsers)
+  useEffect(() => {
+    refresh().catch(() => undefined)
+  }, [])
+
+  return (
+    <div className="glass-panel">
+      <table className="w-full text-left text-sm">
+        <thead className="text-xs uppercase tracking-wider text-slate-500">
+          <tr>
+            <th className="py-2">用户名</th>
+            <th>角色</th>
+            <th>最近登录</th>
+            <th className="text-right">操作</th>
+          </tr>
+        </thead>
+        <tbody>
+          {users.map((u) => (
+            <tr key={u.id} className="border-t border-white/5">
+              <td className="py-2 text-white">{u.username}</td>
+              <td className="text-slate-300">{u.role}</td>
+              <td className="text-slate-400">
+                {u.last_login_at ? new Date(u.last_login_at).toLocaleString() : '从未登录'}
+              </td>
+              <td className="py-2 text-right">
+                <button
+                  className="rounded border border-red-400/40 px-2 py-1 text-xs text-red-400 hover:bg-red-400/10"
+                  onClick={async () => {
+                    if (!confirm(`确定删除「${u.username}」?`)) return
+                    await adminAPI.deleteUser(u.id)
+                    toast.success('已删除')
+                    await refresh()
+                  }}
+                >
+                  <Trash2 size={12} />
+                </button>
+              </td>
+            </tr>
+          ))}
+        </tbody>
+      </table>
+    </div>
+  )
+}
+
+function SettingsPanel() {
+  const [items, setItems] = useState<{ key: string; value: string }[]>([])
+  const [k, setK] = useState('')
+  const [v, setV] = useState('')
+
+  const refresh = () => adminAPI.listSettings().then(setItems)
+  useEffect(() => {
+    refresh().catch(() => undefined)
+  }, [])
+
+  const onSave = async (e: FormEvent) => {
+    e.preventDefault()
+    await adminAPI.updateSetting(k, v)
+    toast.success('已保存')
+    setK('')
+    setV('')
+    await refresh()
+  }
+
+  return (
+    <div className="space-y-4">
+      <form onSubmit={onSave} className="glass-panel grid gap-3 md:grid-cols-3">
+        <input
+          required
+          className="input-base"
+          placeholder="键 (如 tmdb_api_key)"
+          value={k}
+          onChange={(e) => setK(e.target.value)}
+        />
+        <input
+          required
+          className="input-base"
+          placeholder="值"
+          value={v}
+          onChange={(e) => setV(e.target.value)}
+        />
+        <button type="submit" className="neon-button">
+          保存
+        </button>
+      </form>
+      <div className="glass-panel">
+        <table className="w-full text-left text-sm">
+          <thead className="text-xs uppercase tracking-wider text-slate-500">
+            <tr>
+              <th className="py-2">键</th>
+              <th>值</th>
+            </tr>
+          </thead>
+          <tbody>
+            {items.map((it) => (
+              <tr key={it.key} className="border-t border-white/5">
+                <td className="py-2 text-white">{it.key}</td>
+                <td className="text-slate-300">{it.value}</td>
+              </tr>
+            ))}
+          </tbody>
+        </table>
+      </div>
+    </div>
+  )
+}