feat(start): 补齐竖屏背景图（portrait 全套 webp）并重新验证部署

- portrait/ 加入 No.1~5.webp + Night.webp（由 Pictures/portrait 源图
  用 sharp 转 webp，quality 82，体积 ~0.1~0.6MB）
- 前端 build 后两套图（landscape/portrait）均打包，已部署到
  8.130.143.54:8548 并验证（title=CCStart，health 200）
- 更新部署文档：重新验证日期、portrait 集说明、转换工具改用 sharp

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

docs/superpowers/plans/2026-06-18-deploy.md

@@ -231,7 +231,7 @@ ssh root@8.130.143.54 "tail -f /opt/internet-project/server.log"
 **Redeploy after code changes:**
 Re-run Tasks 1–4. For frontend-only changes, skip Task 2.
 
-**Frontend-only redeploy (verified 2026-06-22):**
+**Frontend-only redeploy (re-verified 2026-06-23):**
 The active WSL checkout is at `/home/cc/InternetProject` (not the `/mnt/f/...`
 path in the original tasks above). Since the Rust process serves `static/` from
 disk, a frontend-only change needs **no server restart** — just rebuild and
@@ -252,5 +252,8 @@ A helper exists on the server: `/opt/internet-project/restart_rust.sh`. The
 previous binary is kept as `RustServer.bak` for rollback.
 
 > Startpage backgrounds: large PNG/JPG source images are pre-compressed to WebP
-> (max width 2560, quality ~82) before building — keeps each background under
+> (quality ~82) before building — keeps each background under ~600 KB for the
-> ~400 KB for the 3 Mbps server link.
+> 3 Mbps server link. Two sets live under `Client/src/assets/startpage/`:
+> `landscape/` and `portrait/` (same filenames `No.1~5.webp` + `Night.webp`).
+> As of 2026-06-23 both sets are fully populated; `sharp` is the converter (no
+> system `cwebp`/ImageMagick in this WSL — install it on the fly if needed).