docs: 更新需求文档至v0.5并归档开发进度；修复大文件上传与二维码海报

- 需求文档升级到 v0.5：补充二维码海报保存文件名默认格式、大文件上传三层限制（IIS+ASP.NET+前端）部署约束、新增第11章开发进度状态归档（已上线功能/已修复缺陷/已知限制/后续优化）
- 后端 FileController.Upload 增加 [RequestFormLimits(MultipartBodyLengthLimit=220_200_960)]，修复>128MB multipart 上传被拒
- 前端 UploadView 二维码海报：修正 drawImage 缩放错位、顶部logo/标题垂直居中、分区标题间距、大小与有效期分行显示；保存文件名改为 文传易取件码-取件码(原文件名)-流水号.png
- 新增部署脚本：apply_backend.ps1 / force_dll.ps1（app_offline 解锁DLL）/ ftp_fe.ps1 / ftp_diag.ps1 / ftp_apply.ps1 / _diag/check_dll.ps1

(部署手册 IIS部署与FTP发布.md 仅含编码/BOM 差异，未纳入本次提交)

deploy/ftp_fe.ps1

@@ -0,0 +1,41 @@
+# Upload frontend build (nested wwwroot) - overwrite index.html, upload new assets, delete old ones
+$ErrorActionPreference = "Continue"
+$FtpHost="116.198.221.125"; $FtpPort=21; $FtpUser="wenchuanyi"; $FtpPass="r7P^f*v7rFts"
+$Dist = "D:\CodeBuddy\Pros\WenChuanyi\frontend\dist"
+function NewR($p,$m,$to=90000){ $u="ftp://${FtpHost}:${FtpPort}/"+$p.TrimStart('/'); $r=[System.Net.FtpWebRequest]::Create($u); $r.Method=$m; $r.Credentials=New-Object System.Net.NetworkCredential($FtpUser,$FtpPass); $r.UsePassive=$true; $r.UseBinary=$true; $r.KeepAlive=$false; $r.Timeout=$to; $r }
+function GetSizeF($p){
+  try{ $r=NewR $p ([System.Net.WebRequestMethods+Ftp]::GetFileSize) 30000; $resp=$r.GetResponse(); $s=$resp.ContentLength; $resp.Close(); return $s }
+  catch{ return -1 }
+}
+function DelF($p){
+  try{ $r=NewR $p ([System.Net.WebRequestMethods+Ftp]::DeleteFile); $resp=$r.GetResponse(); try{$resp.Close()}catch{}; Write-Host "DEL $p" }
+  catch{ Write-Host "DEL skip $p (not exist or locked)" }
+  Start-Sleep -Milliseconds 500
+}
+function UpF($lp,$rp){
+  $want=(Get-Item $lp).Length
+  DelF $rp
+  Start-Sleep -Seconds 1
+  for($i=1;$i -le 4;$i++){
+    try{
+      $r=NewR $rp ([System.Net.WebRequestMethods+Ftp]::UploadFile) 300000
+      $b=[IO.File]::ReadAllBytes($lp); $r.ContentLength=$b.Length
+      $s=$r.GetRequestStream(); try{ $s.Write($b,0,$b.Length) } finally { $s.Close() }
+      $resp=$r.GetResponse(); try{ $resp.Close() }catch{}
+      Start-Sleep -Milliseconds 500
+      $after=GetSizeF $rp
+      if($after -eq $want){ Write-Host "UP OK $rp ($after bytes)"; return $true }
+      Write-Host "SIZE MISMATCH $rp got=$after want=$want"
+    }catch{ Write-Host "RETRY($i) $rp : $($_.Exception.Message)" }
+    Start-Sleep -Seconds 3
+  }
+  Write-Host "FAIL $rp"; return $false
+}
+# upload new dist
+$ok=$true
+$ok=(UpF "$Dist\index.html" "/wwwroot/wwwroot/index.html") -and $ok
+$ok=(UpF "$Dist\assets\index-DmgEpwV6.js" "/wwwroot/wwwroot/assets/index-DmgEpwV6.js") -and $ok
+$ok=(UpF "$Dist\assets\index-BjMMI5BR.css" "/wwwroot/wwwroot/assets/index-BjMMI5BR.css") -and $ok
+# remove stale old-hash assets
+DelF "/wwwroot/wwwroot/assets/index-C2wmSVTP.js"
+if($ok){ Write-Host "FE DEPLOY OK" } else { Write-Host "FE DEPLOY PARTIAL" }