chore: release v1.0.15

- settings: backgroundImage/backgroundImageOpacity (10..100, default 60)
- main: otimg:// protocol serves only the configured background file
  (path-allowlisted, 403 otherwise); dev http origin cannot load file:
- TerminalView: allowTransparency + transparent theme background while an
  image is set; .term-bg-image layer behind the xterm surface
- terminal.css: .has-bg-image keeps .xterm-viewport transparent — the old
  chrome-bg pin covered the image layer (root cause of image not showing)
- ThemeSettingsTab: image picker + opacity slider
- ThemeEditor: duplicate-name hint now covers builtin names too; seed
  colors normalized to #rrggbb
- settingsStore: sanitize theme colors, reject non-hex values

CHANGELOG.en.md

@@ -1,5 +1,47 @@
 # OpenTerminal Changelog
 
+## v1.0.15 - 2026-09-20
+
+- **Custom terminal background image**: Settings → Theme → Background image lets you use any local image as the terminal background, with 10%–100% image opacity control; removing the image restores the solid background
+- **Duplicate-name warning in the theme editor**: creating or renaming a theme that collides with a builtin or another custom theme now shows a hint (saving is still allowed)
+- Theme editor seed colors are normalized; invalid color values can no longer enter custom themes
+- Corrupted custom theme colors are auto-repaired to defaults with a warning logged
+
+- The selected item in the settings dialog's left navigation is now white, matching the contrast of unselected items (fixes unreadable blue text on dark backgrounds)
+- New background-image and opacity controls ship with localized strings in all four languages (zh-CN / zh-TW / en / ja)
+
+- Added freeze-duration probes for the renderer and main process to help diagnose future "not responding" reports
+
+## v1.0.14 - 2026-09-20
+
+- Fixed silent corruption of uploaded files **larger than ~250KB** (size looked correct but the content had scrambled bytes)
+- Fixed a remote file-handle leak on every download and a leftover SFTP channel after every transfer; a malformed server response no longer crashes the whole app
+- Uploading over an existing file now asks for confirmation; partially failed multi-file deletes are now reported
+- Permission editor fixes: files with unknown mode no longer get a stray `chmod 000`; an empty GID is no longer replaced by the new UID; setuid / setgid / sticky bits are shown and preserved
+- chmod / chown now time out instead of spinning forever
+
+- Fixed Chinese output over SSH turning into mojibake (multi-byte chars split across network chunks)
+- Fixed command history being lost or corrupted after accepting a Tab completion
+- Fixed editing keys (Ctrl+U / Ctrl+W, …) being written into command history (the "two commands merged" entries)
+- `cd ~/dir` and `cd $HOME/...` are now remembered; new terminals restore them
+- URL click ranges inside lines containing CJK characters no longer shift; degenerate sizes are no longer sent when the window is tiny
+- SSH sessions report the real exit code; ZMODEM timeouts no longer dump garbage into the terminal or the log
+
+- A failed session restore no longer disables snapshot saving for the whole run
+- Monitor CPU / network history charts now redraw live; polling stops while the SSH workspace is hidden
+- Broadcast: closing one pane of a split no longer drops the other from broadcast targets; unchecking one target no longer clears the rest
+- Connection failures show the real reason; double-clicks no longer open duplicate sessions
+- Fixed "Close others / Close right" skipping tabs
+- Language switches apply from the first frame; active-tab text adapts after a theme switch (no more unreadable labels on light themes)
+- The private-key path field no longer claims to be a server-side path
+
+- File drops can no longer navigate the window; external links are limited to http(s) / ftp; IPC is sender-checked
+- Stored passwords are only used for password-auth bookmarks (key-auth bookmarks no longer fall back to sending a password)
+- Connections / known hosts are written atomically — a crash can no longer wipe them
+- A crashed renderer has all of its sessions and logs reclaimed automatically
+- A corrupted custom theme no longer prevents the app from starting
+- Update-channel publishing is atomic — a failed publish can no longer break auto-update
+
 ## v1.0.13 - 2026-09-20
 
 - Simplified Chinese, Traditional Chinese, English and Japanese, switchable in Settings → System → Language; applies instantly and persists

CHANGELOG.ja.md

@@ -1,5 +1,47 @@
 # OpenTerminal 更新履歴
 
+## v1.0.15 - 2026-09-20
+
+- **ターミナルの背景画像をカスタマイズ**：設定 → テーマ → 背景画像で、任意のローカル画像をターミナルの背景に指定でき、画像の不透明度（10%～100%）も調整可能。画像を削除すると単色背景に戻ります
+- **テーマエディターの名前重複警告**：新規作成・編集時に内蔵テーマや他のテーマと名前が重複すると黄色のヒントを表示（保存は可能）
+- テーマエディターのシードカラーを自動正規化し、無効なカラー値がカスタムテーマに入らないように
+- 破損したカスタムテーマのカラーはデフォルト色に自動修復され、警告ログを記録
+
+- 設定ダイアログ左側ナビの選択中項目の文字を白色に変更し、未選択項目と同じコントラストに（濃い背景で青い文字が見えにくい問題を修正）
+- 背景画像・不透明度などの新規コントロールと4言語（簡体字/繁体字/英語/日本語）の文言を同時リリース
+
+- レンダラーとメインプロセスにフリーズ時間の検出ログを追加し、「応答なし」問題の今後の診断に役立てます
+
+## v1.0.14 - 2026-09-20
+
+- **約 250KB を超える**アップロードファイルが静かに破損する問題を修正（サイズは正しいのに内容のバイトが乱れる）
+- ダウンロードのたびにリモートのファイルハンドルが漏出し、転送のたびに SFTP チャネルが残る問題を修正。サーバーのプロトコル異常でアプリ全体が落ちることもなくなりました
+- 同名ファイルへのアップロードは上書き確認を表示。複数ファイル削除の部分失敗も正しく報告されます
+- 権限エディタの修正：不明なモードのファイルに誤って `chmod 000` を送らない。空の GID が新しい UID で置き換えられない。setuid / setgid / sticky ビットを表示・保持
+- chmod / chown にタイムアウトを追加し、遠端の無応答で永久にスピンしなくなりました
+
+- SSH 出力の日本語・中文が文字化けする問題を修正（ネットワークパケットをまたいで分割されたマルチバイト文字）
+- Tab 補完を確定した後にコマンド履歴が失われる・壊れる問題を修正
+- Ctrl+U / Ctrl+W などの編集キーがコマンド履歴に書き込まれる問題を修正（「2 つのコマンドが連結される」症状）
+- `cd ~/ディレクトリ` や `cd $HOME/...` が正しく記憶され、新しいターミナルで復元されます
+- CJK 文字を含む行内のリンクのクリック範囲がずれない。極端に小さいサイズをターミナルに送らない
+- SSH セッションは実際の終了コードを表示。ZMODEM のタイムアウト・エラーでターミナルやログに文字化けを流し込まない
+
+- セッション復元に失敗しても、その実行中のスナップショット保存が止まらなくなりました
+- モニターの CPU / ネットワーク履歴グラフがリアルタイムに再描画されます。SSH ワークスペース非表示中はポーリングを停止
+- ブロードキャスト：SSH 分割の片方を閉じてももう片方がブロードキャスト対象に残ります。チェックを外しても他の選択をクリアしない
+- 接続失敗時に実際の理由を表示。ダブルクリックで重複接続しない
+- 「他を閉じる / 右側を閉じる」がタブを飛ばして閉じる問題を修正
+- 言語切り替えが最初のフレームから有効。テーマ切り替え後にアクティブタブの文字色が自動で調整され、明るいテーマでも読める
+- 秘密鍵パス欄の説明を「この PC 上のパス」に修正（以前はサーバー上のパスと表示され、その通り入力すると接続に失敗していました）
+
+- ウィンドウへのファイル ドロップによるナビゲーションを禁止。外部リンクは http(s) / ftp のみ。IPC に送信元チェックを追加
+- 保存パスワードはパスワード認証のブックマークにのみ使用（鍵認証のブックマークがパスワードをフォールバック送信しない）
+- 接続ブックマークやホスト指紋をアトミックに書き込み、クラッシュでデータが消えない
+- レンダラープロセスの異常終了時に、そのセッションとログを自動回収
+- 破損したカスタムテーマでアプリが起動しなくなる問題を修正
+- 更新チャネルの公開をアトミックに。公開中の失敗で自動更新が使えなくなることはなくなりました
+
 ## v1.0.13 - 2026-09-20
 
 - 簡体字中国語 / 繁体字中国語 / English / 日本語 に対応。設定 → システム → 表示言語 から切り替え、即時反映され保存されます

CHANGELOG.md

@@ -1,5 +1,47 @@
 # OpenTerminal 更新日志
 
+## v1.0.15 - 2026-09-20
+
+- **自定义终端背景图片**：设置 → 主题 → 背景图片，可为终端指定任意本地图片作为背景，并支持 10%–100% 的图片不透明度调节；移除图片后恢复纯色背景
+- **主题编辑器重名提醒**：新建/编辑主题与内置或其他主题重名时给出黄色提示（仍可保存）
+- 主题编辑器种子颜色自动规范化，非法颜色值不再能进入自定义主题
+- 自定义主题颜色数据损坏时自动修复为默认色，并记录告警日志
+
+- 设置弹窗左侧导航选中项文字改为白色，与未选中项对比度一致（修复蓝色文字在深色背景上看不清的问题）
+- 设置弹窗背景图片、透明度等新增控件与四语言（简/繁/英/日）文案同步上线
+
+- 渲染进程与主进程新增冻结时长探测日志，便于后续诊断"卡死无响应"类问题
+
+## v1.0.14 - 2026-09-20
+
+- 修复上传 **大于约 250KB** 的文件会被静默损坏的问题（文件大小正确但内容出现字节错乱）
+- 修复每次下载泄漏一个远端文件句柄、每次传输遗留一个 SFTP 通道的问题；服务器协议异常不再导致整个应用退出
+- 上传遇到同名文件时先询问是否覆盖；删除多个文件时部分失败会如实报告
+- 权限编辑修复：未知权限的文件不再误发 `chmod 000`；GID 留空不再被误改成 UID 的值；正确显示并保留 setuid / setgid / sticky 特殊位
+- chmod / chown 增加超时，远端无响应不再永久转圈
+
+- 修复 SSH 输出中文乱码（跨网络包被截断的多字节字符）
+- 修复按 Tab 接受补全后命令历史丢失或记录错乱的问题
+- 修复 Ctrl+U / Ctrl+W 等编辑键被写进命令历史（表现为历史里出现"两条命令拼接"）
+- `cd ~/目录`、`cd $HOME/...` 现在能正确记忆目录，新终端按此恢复
+- 中文行内的网址链接点击范围不再错位；窗口尺寸过小时不再向终端发送异常尺寸
+- SSH 会话退出时显示真实退出码；ZMODEM 超时/出错不再向终端和日志倾倒乱码
+
+- 启动恢复失败不再导致本次运行期间会话快照永久停止保存
+- 监控面板 CPU / 网络历史曲线现在会实时重绘；切到本地终端工作区时停止向服务器轮询
+- 广播输入：SSH 分屏关闭一侧不再让另一侧丢失广播目标；取消勾选一个目标不再清空其余选择
+- 连接失败时显示真实原因（密码错误 / 拒绝连接等），双击不再重复创建连接
+- 修复"关闭其他 / 关闭右侧"会漏关标签的问题
+- 界面语言切换首帧即生效；切换主题后活动标签文字颜色自动适配，不再出现浅色主题下看不清
+- 私钥路径字段提示纠正为"本机路径"（此前提示为服务器路径，照做会连接失败）
+
+- 禁止把文件拖入窗口导航；外部链接仅允许 http(s) / ftp；IPC 增加来源校验
+- 仅密码认证的连接才使用存储的密码（密钥认证的连接不再回退发送密码）
+- 连接书签、主机指纹等配置改为原子写入，崩溃不再导致数据丢失
+- 渲染进程异常退出时自动回收其全部终端会话与日志
+- 自定义主题数据损坏不再导致应用无法启动
+- 内置更新通道发布改为原子操作，发布中途失败不再导致自动更新不可用
+
 ## v1.0.13 - 2026-09-20
 
 - 支持简体中文 / 繁體中文 / English / 日本語，入口在「设置 → 系统 → 界面语言」，切换即时生效并持久化

CHANGELOG.zh-TW.md

@@ -1,5 +1,47 @@
 # OpenTerminal 更新日誌
 
+## v1.0.15 - 2026-09-20
+
+- **自訂終端機背景圖片**：設定 → 主題 → 背景圖片，可為終端機指定任意本機圖片作為背景，並支援 10%–100% 的圖片不透明度調整；移除圖片後恢復純色背景
+- **主題編輯器重名提醒**：新增/編輯主題與內建或其他主題重名時顯示黃色提示（仍可儲存）
+- 主題編輯器種子顏色自動規範化，非法顏色值不再能進入自訂主題
+- 自訂主題顏色資料損壞時自動修復為預設色，並記錄警告日誌
+
+- 設定彈窗左側導覽選取項文字改為白色，與未選取項對比一致（修復藍色文字在深色背景上看不清的問題）
+- 背景圖片、透明度等新控件與四種語言（簡/繁/英/日）文案同步上線
+
+- 渲染程序與主程序新增凍結時長探測日誌，便於後續診斷「卡死無反應」類問題
+
+## v1.0.14 - 2026-09-20
+
+- 修復上傳 **大於約 250KB** 的檔案會被靜默損壞的問題（檔案大小正確但內容出現位元組錯亂）
+- 修復每次下載洩漏一個遠端檔案句柄、每次傳輸遺留一個 SFTP 通道的問題；伺服器協定異常不再導致整個應用結束
+- 上傳遇到同名檔案時先詢問是否覆蓋；刪除多個檔案時部分失敗會如實報告
+- 權限編輯修復：未知權限的檔案不再誤發 `chmod 000`；GID 留空不再被誤改成 UID 的值；正確顯示並保留 setuid / setgid / sticky 特殊位
+- chmod / chown 增加逾時，遠端無回應不再永久轉圈
+
+- 修復 SSH 輸出中文亂碼（跨網路封包被截斷的多位元組字元）
+- 修復按 Tab 接受補全後命令歷史丟失或記錯亂的問題
+- 修復 Ctrl+U / Ctrl+W 等編輯鍵被寫進命令歷史（表現為歷史裡出現「兩條命令拼接」）
+- `cd ~/目錄`、`cd $HOME/...` 現在能正確記憶目錄，新終端按此恢復
+- 中文行內的網址連結點擊範圍不再錯位；視窗尺寸過小時不再向終端發送異常尺寸
+- SSH 連線結束時顯示真實離開代碼；ZMODEM 逾時/出錯不再向終端和日誌傾倒亂碼
+
+- 啟動恢復失敗不再導致本次執行期間工作階段快照永久停止儲存
+- 監控面板 CPU / 網路歷史曲線現在會即時重繪；切到本地終端工作區時停止向伺服器輪詢
+- 廣播輸入：SSH 分屏關閉一側不再讓另一側丟失廣播目標；取消勾選一個目標不再清空其餘選擇
+- 連線失敗時顯示真實原因（密碼錯誤／拒絕連線等），雙擊不再重複建立連線
+- 修復「關閉其他 / 關閉右側」會漏關標籤的問題
+- 介面語言切換首影格即生效；切換主題後活動標籤文字顏色自動適配，不再出現淺色主題下看不清
+- 私鑰路徑欄位提示更正為「本機路徑」（此前提示為伺服器路徑，照做會連線失敗）
+
+- 禁止把檔案拖入視窗導覽；外部連結僅允許 http(s) / ftp；IPC 增加來源校驗
+- 僅密碼認證的連線才使用儲存的密碼（金鑰認證的連線不再回退發送密碼）
+- 連線書籤、主機指紋等設定改為原子寫入，當機不再導致資料丟失
+- 渲染程序異常結束時自動回收其全部終端連線與日誌
+- 自訂主題資料損壞不再導致應用無法啟動
+- 內建更新通道發布改為原子操作，發布中途失敗不再導致自動更新不可用
+
 ## v1.0.13 - 2026-09-20
 
 - 支援簡體中文 / 繁體中文 / English / 日本語，入口在「設定 → 系統 → 介面語言」，切換即時生效並持久化

package-lock.json

@@ -1,12 +1,12 @@
 {
   "name": "open-terminal",
-  "version": "1.0.13",
+  "version": "1.0.14",
   "lockfileVersion": 3,
   "requires": true,
   "packages": {
     "": {
       "name": "open-terminal",
-      "version": "1.0.13",
+      "version": "1.0.14",
       "license": "MIT",
       "dependencies": {
         "@lydell/node-pty": "^1.2.0-beta.15",

package.json

@@ -1,7 +1,7 @@
 {
   "name": "open-terminal",
   "productName": "OpenTerminal",
-  "version": "1.0.13",
+  "version": "1.0.15",
   "description": "Open-source terminal with SSH, split panes, themes and fonts",
   "main": "out/main/index.js",
   "author": "Bill",

scripts/release.cjs

@@ -200,21 +200,35 @@ async function giteaChannel() {
   for (const [f, name] of ordered) {
     const stat = fs.statSync(f)
     const url = `${base}/${encodeURIComponent(name)}`
-    const resp = await fetch(url, {
-      method: 'PUT',
-      headers: { Authorization: `token ${env.GIT_TOKEN}`, 'Content-Type': 'application/octet-stream', 'Content-Length': String(stat.size) },
-      body: fs.createReadStream(f),
-      duplex: 'half'
-    })
+    const put = async () =>
+      fetch(url, {
+        method: 'PUT',
+        headers: { Authorization: `token ${env.GIT_TOKEN}`, 'Content-Type': 'application/octet-stream', 'Content-Length': String(stat.size) },
+        body: fs.createReadStream(f),
+        duplex: 'half'
+      })
+    let resp = await put()
     console.log(`  put ${name}: HTTP ${resp.status}`)
+    if (!resp.ok && (resp.status === 409 || resp.status === 422)) {
+      if (/\d+\.\d+\.\d+/.test(name)) {
+        // Version-named payloads are immutable per release: accept a stored
+        // copy only when it has exactly the same size.
+        if ((await channelFileSize(url)) === stat.size) {
+          console.log(`  ${name} is already published with the same size, kept`)
+          continue
+        }
+      } else {
+        // latest.yml / release-notes.md change every release and the atomic
+        // flow no longer wipes the channel up front, so replace them in place.
+        // The swap window is one small file (sub-second), not the whole channel.
+        const del = await fetch(url, { method: 'DELETE', headers: { Authorization: `token ${env.GIT_TOKEN}` } })
+        console.log(`  delete old ${name}: HTTP ${del.status}`)
+        resp = await put()
+        console.log(`  put ${name}: HTTP ${resp.status}`)
+      }
+    }
     if (!resp.ok) {
       const detail = (await resp.text()).slice(0, 200)
-      // Re-publishing the same version can hit an already-stored file; accept it
-      // only when the stored copy has exactly the same size.
-      if ((resp.status === 409 || resp.status === 422) && (await channelFileSize(url)) === stat.size) {
-        console.log(`  ${name} is already published with the same size, kept`)
-        continue
-      }
       throw new Error(`channel put failed (${resp.status}) for ${name}: ${detail}`)
     }
   }

src/main/index.ts

@@ -1,6 +1,7 @@
-import { app, BrowserWindow, globalShortcut, nativeImage, shell } from 'electron'
+import { app, BrowserWindow, globalShortcut, net, nativeImage, protocol, shell } from 'electron'
 import { existsSync } from 'fs'
 import { join } from 'path'
+import { pathToFileURL } from 'url'
 import { isTrustedRendererUrl, registerIpc } from './ipc'
 import { killAllPtys, killPtysByOwner } from './pty'
 import { applyStartupSystemSettings, loadSettings } from './settingsStore'
@@ -45,6 +46,14 @@ if (!app.isPackaged) {
   app.setPath('userData', join(app.getPath('appData'), 'OpenTerminal-dev'))
 }
 
+// Custom background image (设置 → 主题): the renderer page cannot load file:
+// subresources directly (Chromium blocks them from non-file origins), so it
+// references them through this scheme instead. The handler serves exactly one
+// file — the configured background image — nothing else.
+protocol.registerSchemesAsPrivileged([
+  { scheme: 'otimg', privileges: { secure: true, supportFetchAPI: false, corsEnabled: false } }
+])
+
 // Single instance: a second launch just surfaces the existing window (pulls
 // it out of the tray if hidden there) instead of starting another process.
 // The refused instance skips the whole startup path: `app.quit()` only asks
@@ -57,6 +66,19 @@ if (!gotSingleInstanceLock) {
   app.on('second-instance', () => showOrCreate())
 
   app.whenReady().then(() => {
+    // Serve the configured background image (path lives in settings; anything
+    // else — including a path that is no longer configured — is refused, so the
+    // protocol cannot be used to read arbitrary files).
+    protocol.handle('otimg', (request) => {
+      const url = new URL(request.url)
+      const requested = decodeURIComponent(url.pathname.replace(/^\//, ''))
+      const allowed = loadSettings().terminal.backgroundImage
+      if (allowed === '' || requested !== allowed || !existsSync(requested)) {
+        return new Response('', { status: 403 })
+      }
+      return net.fetch(pathToFileURL(requested).toString())
+    })
+
     registerIpc()
     registerUpdateIpc()
     // Before the window exists: a renderer-triggered check must not run against
@@ -167,6 +189,18 @@ process.on('uncaughtException', (err) => {
   console.error('[main] uncaughtException:', err)
 })
 
+// Diagnostics for "app froze then recovered" reports: WER logs an
+// AppHangTransient but keeps no stack. A stall of THIS (UI) thread is what
+// Windows flags as a hang, so measure event-loop lag and say so loudly when
+// it happens — that distinguishes a main-process block from a renderer one.
+let lastTick = Date.now()
+setInterval(() => {
+  const now = Date.now()
+  const lag = now - lastTick - 1000
+  if (lag > 2000) console.error(`[main] event loop stalled ~${lag}ms`)
+  lastTick = now
+}, 1000).unref()
+
 app.on('before-quit', () => {
   // Let window 'close' events pass through so teardown completes.
   markQuitting()

src/main/settingsStore.ts

@@ -138,11 +138,15 @@ function sanitizeThemes(value: unknown, warnings: Warnings): TerminalTheme[] {
         : null
     const colors: ThemeColors = { ...DEFAULT_DARK.colors }
     const target = colors as unknown as Record<string, string>
+    const HEX_COLOR = /^#(?:[0-9a-f]{3}|[0-9a-f]{6}|[0-9a-f]{8})$/i
     for (const key of THEME_COLOR_KEYS) {
       const color = candidate?.[key]
-      if (typeof color === 'string' && color !== '') target[key] = color
-      else if (color !== undefined) {
-        warnings.push(`customThemes[${index}].colors.${key} repaired → built-in default`)
+      // Only well-formed hex colours survive: xterm would render anything else
+      // as black, and the theme editor's native colour input needs #rrggbb.
+      if (typeof color === 'string' && HEX_COLOR.test(color.trim())) {
+        target[key] = color.trim()
+      } else if (color !== undefined) {
+        warnings.push(`customThemes[${index}].colors.${key}: not a hex color — repaired`)
       }
     }
     themes.push({

src/renderer/index.html

@@ -5,7 +5,7 @@
     <title>OpenTerminal</title>
     <meta
       http-equiv="Content-Security-Policy"
-      content="default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; font-src 'self' data:"
+      content="default-src 'self'; script-src 'self'; style-src 'self' 'unsafe-inline'; font-src 'self' data:; img-src 'self' file: data: otimg:"
     />
   </head>
   <body>

src/renderer/src/App.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useState, useSyncExternalStore } from 'react'
+import { useEffect, useState } from 'react'
 import { ConfigProvider } from 'antd'
 import zhCN from 'antd/locale/zh_CN'
 import zhTW from 'antd/locale/zh_TW'
@@ -9,7 +9,7 @@ import { SettingsDialog } from '@renderer/settings/SettingsDialog'
 import { TransferPanel } from '@renderer/sftp/TransferPanel'
 import { useSettingsStore } from '@renderer/settings/store'
 import { getThemeById } from '@shared/theme'
-import { DEFAULT_LANGUAGE, getLanguage, onLanguageChange, setLanguage, type Language } from '@shared/i18n'
+import { DEFAULT_LANGUAGE, syncLanguage, type Language } from '@shared/i18n'
 import { applyChromeTheme, applyTabAccent } from '@renderer/theme/chrome'
 import appIconUrl from '../../../build/icon.png'
 
@@ -50,10 +50,11 @@ export default function App(): React.JSX.Element {
   }, [hydrate])
 
   // Interface language: t() reads the module-level language at render time, so
-  // sync it before the tree renders — an effect would paint one frame late. The
-  // subscription re-renders every t() caller when the language changes elsewhere.
-  if (getLanguage() !== storedLanguage) setLanguage(storedLanguage)
-  const language = useSyncExternalStore(onLanguageChange, getLanguage)
+  // sync it before the tree renders — an effect would paint one frame late.
+  // Silent on purpose: notifying subscribers during a render is what React
+  // warns about; every language change re-renders App via the settings store.
+  syncLanguage(storedLanguage)
+  const language = storedLanguage
   useEffect(() => {
     document.documentElement.lang = language
   }, [language])

src/renderer/src/main.tsx

@@ -11,6 +11,19 @@ import { useSettingsStore } from './settings/store'
 import { mix } from './theme/chrome'
 import './global.css'
 
+// Diagnostics: report renderer main-thread freezes after recovery. console.error
+// is surfaced into the dev terminal by the main process's console-message hook,
+// so a "卡死又恢复" report tells us which process stalled and for how long.
+{
+  let lastTick = performance.now()
+  setInterval(() => {
+    const now = performance.now()
+    const lag = now - lastTick - 2000
+    if (lag > 3000) console.error(`[renderer] main thread stalled ~${Math.round(lag)}ms`)
+    lastTick = now
+  }, 2000)
+}
+
 // Dev convenience: allow opening the renderer in a plain browser (vite page)
 // so layout/UX work doesn't require the electron shell. No-op under electron.
 if (typeof window !== 'undefined' && !window.api) {

src/renderer/src/settings/ThemeSettingsTab.tsx

@@ -1,5 +1,5 @@
 import { useMemo } from 'react'
-import { Button, ColorPicker, Popconfirm } from 'antd'
+import { Button, ColorPicker, Popconfirm, Slider } from 'antd'
 import { t } from '@shared/i18n'
 import type { TerminalSettings } from '@shared/settings'
 import { DEFAULT_SETTINGS } from '@shared/settings'
@@ -46,8 +46,45 @@ export function ThemeSettingsTab({
     await setCustomThemes(next)
   }
 
+  const pickImage = async (): Promise<void> => {
+    const files = await window.api.pickFiles()
+    const image = files.find((f) => /\.(png|jpe?g|bmp|gif|webp|avif)$/i.test(f))
+    if (image) await updateTerminal({ backgroundImage: image })
+  }
+
   return (
     <div className="theme-pane">
+      <div className="theme-accent-row">
+        <div>
+          <div className="settings-block-label">{t('settings.theme.backgroundImage')}</div>
+          <div className="settings-block-hint">{t('settings.theme.backgroundImageDesc')}</div>
+        </div>
+        <div className="theme-accent-controls">
+          <Button size="small" onClick={() => void pickImage()}>
+            {t('settings.theme.chooseImage')}
+          </Button>
+          {settings.terminal.backgroundImage !== '' && (
+            <Button size="small" onClick={() => void updateTerminal({ backgroundImage: '' })}>
+              {t('settings.theme.clearImage')}
+            </Button>
+          )}
+        </div>
+      </div>
+      {settings.terminal.backgroundImage !== '' && (
+        <div className="theme-accent-row">
+          <div>
+            <div className="settings-block-label">{t('settings.theme.imageOpacity')}</div>
+          </div>
+          <Slider
+            style={{ width: 200 }}
+            min={10}
+            max={100}
+            step={5}
+            value={settings.terminal.backgroundImageOpacity}
+            onChange={(v) => void updateTerminal({ backgroundImageOpacity: v })}
+          />
+        </div>
+      )}
       <div className="theme-accent-row">
         <div>
           <div className="settings-block-label">{t('settings.theme.accent')}</div>

src/renderer/src/settings/settings.css

@@ -44,6 +44,13 @@
   background: color-mix(in srgb, var(--tab-accent, #3fb950) 16%, transparent);
 }
 
+/* antd paints the active tab label in the primary blue, which is hard to read
+   on the accent-tinted row; keep it identical to the inactive labels. The
+   extra .ant-tabs-tab class out-specifies antd's runtime-injected rule. */
+.settings-body .ant-tabs-left > .ant-tabs-nav .ant-tabs-tab.ant-tabs-tab-active .ant-tabs-tab-btn {
+  color: #ffffff;
+}
+
 .settings-body .ant-tabs-left > .ant-tabs-nav .ant-tabs-ink-bar {
   background: var(--tab-accent, #3fb950);
 }
@@ -575,3 +582,11 @@
 .shortcut-input.is-recording .ant-input {
   border-color: var(--tab-accent, #3fb950);
 }
+
+/* theme editor: duplicate-name notice under the name field */
+.theme-editor-hint {
+  margin: -4px 0 10px;
+  padding-left: 2px;
+  font-size: 12px;
+  color: #d29922;
+}

src/renderer/src/terminal/TerminalView.tsx

@@ -67,8 +67,20 @@ const SEARCH_DECORATIONS: NonNullable<NonNullable<Parameters<SearchAddon['findNe
 // xterm's default overviewRulerBorder (#7f7f7f) renders as a light vertical line
 // on the dark surface once scrollback exists. Force it transparent; search-match
 // marks in the ruler keep their own colors.
-function withChromeColors(colors: ITheme): ITheme {
-  return { ...colors, overviewRulerBorder: '#00000000' }
+function withChromeColors(colors: ITheme, transparentBackground: boolean): ITheme {
+  return {
+    ...colors,
+    overviewRulerBorder: '#00000000',
+    // While a custom background image is set the xterm surface goes fully
+    // transparent so the image layer behind the host is what shows through.
+    ...(transparentBackground ? { background: '#00000000' } : {})
+  }
+}
+
+/** URL for a background image, served by the main process's otimg:// handler
+ *  (the page itself cannot reference file: paths from non-file origins). */
+function toFileUrl(path: string): string {
+  return `otimg://bg/${encodeURIComponent(path)}`
 }
 
 export interface TerminalHandle {
@@ -673,8 +685,9 @@ export const TerminalView: ForwardRefExoticComponent<TerminalViewProps & { ref?:
       cursorBlink: tSettings.cursorBlink,
       cursorStyle: tSettings.cursorStyle,
       cursorInactiveStyle: tSettings.cursorInactiveStyle,
-      theme: withChromeColors(getThemeById(tSettings.themeId, settings.customThemes).colors as ITheme),
+      theme: withChromeColors(getThemeById(tSettings.themeId, settings.customThemes).colors as ITheme, Boolean(tSettings.backgroundImage)),
       allowProposedApi: true,
+      allowTransparency: true,
       overviewRuler: { width: 9, showTopBorder: false, showBottomBorder: false },
       drawBoldTextInBrightColors: true,
       minContrastRatio: 1,
@@ -1009,7 +1022,7 @@ export const TerminalView: ForwardRefExoticComponent<TerminalViewProps & { ref?:
     // Live-appliable in xterm 6: without this the setting only took effect for
     // terminals opened after the change, which reads as "the setting is broken".
     term.options.scrollback = tSettings.scrollback
-    term.options.theme = withChromeColors(getThemeById(tSettings.themeId, settings.customThemes).colors as ITheme)
+    term.options.theme = withChromeColors(getThemeById(tSettings.themeId, settings.customThemes).colors as ITheme, Boolean(tSettings.backgroundImage))
     scheduleFit()
   }, [tSettings, settings.customThemes, scheduleFit])
 
@@ -1048,7 +1061,13 @@ export const TerminalView: ForwardRefExoticComponent<TerminalViewProps & { ref?:
     [sessionId]
   )
 
-  const terminalClassName = useMemo(() => ['terminal-view', className].filter(Boolean).join(' '), [className])
+  const terminalClassName = useMemo(
+    () =>
+      ['terminal-view', settings.terminal.backgroundImage !== '' && 'has-bg-image', className]
+        .filter(Boolean)
+        .join(' '),
+    [className, settings.terminal.backgroundImage]
+  )
 
   /**
    * [M5] Compute and store the floating popup position so it hugs the text
@@ -1277,6 +1296,15 @@ export const TerminalView: ForwardRefExoticComponent<TerminalViewProps & { ref?:
           </div>
         )}
         <div className="terminal-view-dock" ref={hostRef}>
+          {settings.terminal.backgroundImage !== '' && (
+            <div
+              className="term-bg-image"
+              style={{
+                backgroundImage: `url("${toFileUrl(settings.terminal.backgroundImage)}")`,
+                opacity: Math.min(100, Math.max(10, settings.terminal.backgroundImageOpacity)) / 100
+              }}
+            />
+          )}
           {dead && (
             <div className="term-dead-mask">
               <div>{t('terminal.dead.message', { code: exitCode })}</div>

src/renderer/src/terminal/terminal.css

@@ -15,11 +15,17 @@
 
 /* xterm.css defaults .xterm-viewport to #000; when the pane height isn't a
    multiple of the cell height the leftover bottom strip shows that black.
-   Pin it to the (theme-derived) chrome background so the gap is invisible. */
-.terminal-view .xterm .xterm-viewport {
+   Pin it to the (theme-derived) chrome background so the gap is invisible.
+   With a custom background image the viewport must stay transparent — this
+   opaque layer would cover the .term-bg-image behind the xterm surface. */
+.terminal-view:not(.has-bg-image) .xterm .xterm-viewport {
   background-color: var(--chrome-bg);
 }
 
+.terminal-view.has-bg-image .xterm .xterm-viewport {
+  background-color: transparent;
+}
+
 /* Slim slate scrollbar for the xterm viewport — the native Windows one renders
    light track + arrow buttons that look broken on the dark surface. The thumb
    sits inset inside a wider grab lane (transparent border + padding-box clip)
@@ -353,6 +359,24 @@
   padding: 0;
 }
 
+/* ---- custom background image (设置 → 主题) ----
+   Sits behind the xterm screen; while an image is set the theme background is
+   transparent (allowTransparency), so this layer is what shows through. */
+.term-bg-image {
+  position: absolute;
+  inset: 0;
+  z-index: 0;
+  background-size: cover;
+  background-position: center;
+  background-repeat: no-repeat;
+  pointer-events: none;
+}
+
+.terminal-view-dock > .xterm {
+  position: relative;
+  z-index: 1;
+}
+
 /* ---- dead process overlay ---- */
 .term-dead-mask {
   position: absolute;

src/renderer/src/theme/editor/ThemeEditor.tsx

@@ -2,7 +2,7 @@ import { useEffect, useMemo, useState } from 'react'
 import { Input, Modal } from 'antd'
 import { t } from '@shared/i18n'
 import type { ThemeColors, TerminalTheme } from '@shared/theme'
-import { DEFAULT_DARK, getThemeById } from '@shared/theme'
+import { BUILTIN_THEMES, DEFAULT_DARK, getThemeById } from '@shared/theme'
 import { useSettingsStore } from '../../settings/store'
 
 export interface ThemeEditorProps {
@@ -49,6 +49,17 @@ const ANSI_KEYS: FieldSpec[] = [
   { key: 'brightWhite', label: 'Bright White' }
 ]
 
+/** The native colour input only accepts #rrggbb: clamp every seeded value so a
+ *  hand-edited or migrated theme can't render the picker as solid black. */
+function normalizeThemeColors(colors: ThemeColors, fallback: ThemeColors): ThemeColors {
+  const out = { ...fallback }
+  for (const key of Object.keys(fallback) as (keyof ThemeColors)[]) {
+    const value = colors[key] ?? ''
+    out[key] = /^#[0-9a-f]{6}$/i.test(value) ? value : (fallback[key] ?? '')
+  }
+  return out
+}
+
 export function ThemeEditor({ open, onClose, themeId }: ThemeEditorProps): React.JSX.Element {
   const settings = useSettingsStore((s) => s.settings)
   const updateTerminal = useSettingsStore((s) => s.updateTerminal)
@@ -64,6 +75,11 @@ export function ThemeEditor({ open, onClose, themeId }: ThemeEditorProps): React
   const [name, setName] = useState('')
   const [colors, setColors] = useState<ThemeColors>(DEFAULT_DARK.colors)
   const [saving, setSaving] = useState(false)
+  /** another theme (builtin or custom) already uses this name (allowed, but the user should know) */
+  const duplicateName =
+    name.trim() !== '' &&
+    (BUILTIN_THEMES.some((th) => th.name === name.trim()) ||
+      settings.customThemes.some((th) => th.id !== themeId && th.name === name.trim()))
 
   // (re)initialize the form each time the modal opens
   useEffect(() => {
@@ -75,12 +91,12 @@ export function ThemeEditor({ open, onClose, themeId }: ThemeEditorProps): React
         return
       }
       setName(editingTheme.name)
-      setColors({ ...editingTheme.colors })
+      setColors(normalizeThemeColors(editingTheme.colors, DEFAULT_DARK.colors))
     } else {
       /** create mode: seed a fresh copy based on the currently active theme */
       const active = getThemeById(settings.terminal.themeId, settings.customThemes)
       setName(active.name + t('settings.themeEditor.copySuffix'))
-      setColors({ ...active.colors })
+      setColors(normalizeThemeColors(active.colors, DEFAULT_DARK.colors))
     }
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [open])
@@ -141,6 +157,7 @@ export function ThemeEditor({ open, onClose, themeId }: ThemeEditorProps): React
             maxLength={60}
           />
         </div>
+        {duplicateName && <div className="theme-editor-hint">{t('settings.themeEditor.duplicateName')}</div>}
 
         <div className="theme-editor-colors">
           {headerKeys().map((spec) => (

src/shared/i18n/dicts/en/settings.ts

@@ -139,12 +139,18 @@ const settings: Record<string, string> = {
   'settings.highlight.builtin.url': 'Web links',
   'settings.theme.accent': 'Tab accent color',
   'settings.theme.accentDesc': 'Accent color for the active tab border, the sidebar indicator, and SSH badges',
+  'settings.theme.backgroundImage': 'Background image',
+  'settings.theme.backgroundImageDesc': 'Show an image behind the terminal; remove it to go back to a solid background',
+  'settings.theme.chooseImage': 'Choose image',
+  'settings.theme.clearImage': 'Remove',
+  'settings.theme.imageOpacity': 'Image opacity',
   'settings.theme.customBadge': 'Custom',
   'settings.theme.deleteTitle': 'Delete custom theme',
   'settings.theme.create': 'New theme',
   'settings.theme.editTitle': 'Edit theme',
   'settings.themeEditor.name': 'Name',
   'settings.themeEditor.namePlaceholder': 'Theme name',
+  'settings.themeEditor.duplicateName': 'Same name as another theme (saving is still allowed)',
   'settings.themeEditor.copySuffix': ' (copy)',
   'settings.about.currentVersion': 'Current version',
   'settings.about.statusIdle': 'Click to check for updates',

src/shared/i18n/dicts/ja/settings.ts

@@ -136,12 +136,18 @@ const settings: Record<string, string> = {
   'settings.highlight.builtin.url': 'ウェブリンク',
   'settings.theme.accent': 'タブのアクセントカラー',
   'settings.theme.accentDesc': 'アクティブなタブの枠線、サイドバーのインジケーター、SSH バッジのアクセントカラー',
+  'settings.theme.backgroundImage': '背景画像',
+  'settings.theme.backgroundImageDesc': 'ターミナルの背後に画像を表示します。削除すると無地の背景に戻ります',
+  'settings.theme.chooseImage': '画像を選択',
+  'settings.theme.clearImage': '削除',
+  'settings.theme.imageOpacity': '画像の不透明度',
   'settings.theme.customBadge': 'カスタム',
   'settings.theme.deleteTitle': 'カスタムテーマを削除',
   'settings.theme.create': '新しいテーマ',
   'settings.theme.editTitle': 'テーマを編集',
   'settings.themeEditor.name': '名前',
   'settings.themeEditor.namePlaceholder': 'テーマ名',
+  'settings.themeEditor.duplicateName': '他のテーマと同名です（保存は可能）',
   'settings.themeEditor.copySuffix': '（コピー）',
   'settings.about.currentVersion': '現在のバージョン',
   'settings.about.statusIdle': 'クリックして更新を確認',

src/shared/i18n/dicts/zh-CN/settings.ts

@@ -133,12 +133,18 @@ const settings: Record<string, string> = {
   'settings.highlight.builtin.url': '网址链接',
   'settings.theme.accent': '标签强调色',
   'settings.theme.accentDesc': '活动标签边框、侧栏指示条与 SSH 徽章的强调颜色',
+  'settings.theme.backgroundImage': '背景图片',
+  'settings.theme.backgroundImageDesc': '为终端设置一张背景图片；移除后恢复纯色背景',
+  'settings.theme.chooseImage': '选择图片',
+  'settings.theme.clearImage': '移除图片',
+  'settings.theme.imageOpacity': '图片不透明度',
   'settings.theme.customBadge': '自定义',
   'settings.theme.deleteTitle': '删除自定义主题',
   'settings.theme.create': '新建主题',
   'settings.theme.editTitle': '编辑主题',
   'settings.themeEditor.name': '名称',
   'settings.themeEditor.namePlaceholder': '主题名称',
+  'settings.themeEditor.duplicateName': '与其他主题重名，仍可保存',
   'settings.themeEditor.copySuffix': '（副本）',
   'settings.about.currentVersion': '当前版本',
   'settings.about.statusIdle': '点击检查更新',

src/shared/i18n/dicts/zh-TW/settings.ts

@@ -133,12 +133,18 @@ const settings: Record<string, string> = {
   'settings.highlight.builtin.url': '網址連結',
   'settings.theme.accent': '標籤強調色',
   'settings.theme.accentDesc': '作用中標籤的邊框、側邊欄指示條與 SSH 徽章的強調顏色',
+  'settings.theme.backgroundImage': '背景圖片',
+  'settings.theme.backgroundImageDesc': '為終端設定一張背景圖片；移除後恢復純色背景',
+  'settings.theme.chooseImage': '選擇圖片',
+  'settings.theme.clearImage': '移除圖片',
+  'settings.theme.imageOpacity': '圖片不透明度',
   'settings.theme.customBadge': '自訂',
   'settings.theme.deleteTitle': '刪除自訂主題',
   'settings.theme.create': '新增主題',
   'settings.theme.editTitle': '編輯主題',
   'settings.themeEditor.name': '名稱',
   'settings.themeEditor.namePlaceholder': '主題名稱',
+  'settings.themeEditor.duplicateName': '與其他主題同名，仍可儲存',
   'settings.themeEditor.copySuffix': '（副本）',
   'settings.about.currentVersion': '目前版本',
   'settings.about.statusIdle': '點擊檢查更新',

src/shared/i18n/index.ts

@@ -70,6 +70,15 @@ export function setLanguage(lang: Language): void {
   for (const listener of listeners) listener(lang)
 }
 
+/** Render-time sync for the React tree: update the module language WITHOUT
+ *  notifying subscribers — firing listeners during another component's render
+ *  makes React warn ("cannot update a component while rendering a different
+ *  component"). Renderer components re-render via the settings store instead;
+ *  the notifying setLanguage stays for the main process (tray rebuild). */
+export function syncLanguage(lang: Language): void {
+  current = lang
+}
+
 export function getLanguage(): Language {
   return current
 }

src/shared/settings.ts

@@ -49,6 +49,10 @@ export interface TerminalSettings {
   showOpenCwdButton: boolean
   /** accent color for the active tab outline, rail indicator and SSH badges */
   tabAccentColor: string
+  /** absolute path to an image rendered behind the terminal; '' = none */
+  backgroundImage: string
+  /** background image layer opacity, 10..100 (%) */
+  backgroundImageOpacity: number
 }
 
 export interface SystemSettings {
@@ -132,7 +136,9 @@ export const DEFAULT_SETTINGS: AppSettings = {
     showRecButton: false,
     showOpenLogsButton: false,
     showOpenCwdButton: true,
-    tabAccentColor: '#3fb950'
+    tabAccentColor: '#3fb950',
+    backgroundImage: '',
+    backgroundImageOpacity: 60
   },
   customThemes: [],
   highlightRules: DEFAULT_HIGHLIGHT_RULES,