feat(web): nav regroup, site RSS tab and site types (IA-2)

- sidebar: 概览 / 获取 / 整理 / 系统. Tasks moves to 系统; sites,
  subscriptions and rules form the 获取 group (ACQUIRE_GROUP_TITLE in
  nav.ts, the single place to rename it); standalone RSS nav item removed
- site detail gets an RSS tab with everything the RSS page had (create,
  edit, enable, fetch now, fetch state) plus recent items; tabs and
  header actions follow the site's capabilities
- old /console/sources links redirect to the site's RSS tab (?feed= looks
  up the owning site) or the site list; task links to RSS point at sites
- site list shows and filters by type; add-site wizard starts with a type
  step (PT still picks from the definition library; public BT / custom
  RSS source only need name, URL and RSS URL)

Co-Authored-By: Claude Opus 5.5 <[email protected]>

apps/web/app/components/sites/site-feed-dialog.tsx

@@ -137,8 +137,10 @@ export function SiteFeedDialog({
                   <span className="break-all">
                     保存后显示为 <span className="font-mono">{shown}</span>
                   </span>
-                ) : (
+                ) : site.kind === "pt" ? (
                   "站点「控制面板 → RSS」里生成的链接"
+                ) : (
+                  "RSS 或 Atom 地址"
                 )
               }
             >
@@ -149,11 +151,13 @@ export function SiteFeedDialog({
                 spellCheck={false}
                 value={url}
                 aria-invalid={!!error}
-                placeholder={`${site.baseUrl.replace(/\/$/, "")}/torrentrss.php?passkey=…`}
+                placeholder={
+                  site.kind === "pt" ? `${site.baseUrl.replace(/\/$/, "")}/torrentrss.php?passkey=…` : "https://"
+                }
                 onChange={(e) => setUrl(e.target.value)}
               />
             </FormField>
-            {mismatch ? (
+            {mismatch && site.kind !== "rss_feed" ? (
               <p className="-mt-1 mb-2 text-caption text-warning">
                 地址域名与 {site.name}（{new URL(site.baseUrl).hostname}）不一致，仍可保存；确认没有填错站点。
               </p>