Add support for suspending LazyGit with Ctrl+Z on Unix systems (#4757)

## ✨ Add Ctrl+Z suspend support for LazyGit on Unix-like systems

### 📝 Summary

This PR adds support for suspending LazyGit when the user presses
`Ctrl+Z`, making it behave like common CLI tools (e.g., Vim, less,
htop):

* Pressing `Ctrl+Z` sends a `SIGTSTP` signal to suspend LazyGit.
* After resuming with `fg`, LazyGit redraws and continues working
without hanging.
* During suspension, background routines are paused to avoid running
while LazyGit is stopped.

### ✅ Motivation

Make LazyGit feel more native on Unix-like systems by supporting
standard terminal suspend/resume (Ctrl+Z / fg) behavior.

Closes #3906

Author: stefanhaller

docs/Config.md

@@ -517,6 +517,7 @@ keybinding:
   universal:
     quit: q
     quit-alt1: <c-c>
+    suspendApp: <c-z>
     return: <esc>
     quitWithoutChangingDirectory: Q
     togglePanel: <tab>
@@ -583,7 +584,7 @@ keybinding:
     nextScreenMode: +
     prevScreenMode: _
     undo: z
-    redo: <c-z>
+    redo: Z
     filteringMenu: <c-s>
     diffingMenu: W
     diffingMenu-alt: <c-e>

docs/keybindings/Keybindings_en.md

@@ -30,9 +30,10 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` W `` | View diffing options | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` <c-e> `` | View diffing options | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` q `` | Quit |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | Toggle whitespace | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | Undo | The reflog will be used to determine what git command to run to undo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
-| `` <c-z> `` | Redo | The reflog will be used to determine what git command to run to redo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
+| `` Z `` | Redo | The reflog will be used to determine what git command to run to redo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
 
 ## List panel navigation
 

docs/keybindings/Keybindings_ja.md

@@ -30,9 +30,10 @@ _凡例：`＜c-b＞` はctrl+b、`＜a-b＞` はalt+b、`B` はshift+bを意味
 | `` W `` | 差分オプションを表示 | ２つのrefの差分に関連するオプションを表示します（例：選択したrefとの差分表示、差分を取るrefの入力、差分方向の反転など）。 |
 | `` <c-e> `` | 差分オプションを表示 | ２つのrefの差分に関連するオプションを表示します（例：選択したrefとの差分表示、差分を取るrefの入力、差分方向の反転など）。 |
 | `` q `` | 終了 |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | 空白表示の切り替え | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | 元に戻す | 最後のgitコマンドを元に戻すために実行するgitコマンドを決定するためにreflogが使用されます。これにはワーキングツリーへの変更は含まれません。コミットのみが考慮されます。 |
-| `` <c-z> `` | やり直す | 最後のgitコマンドをやり直すために実行するgitコマンドを決定するためにreflogが使用されます。これにはワーキングツリーへの変更は含まれません。コミットのみが考慮されます。 |
+| `` Z `` | やり直す | 最後のgitコマンドをやり直すために実行するgitコマンドを決定するためにreflogが使用されます。これにはワーキングツリーへの変更は含まれません。コミットのみが考慮されます。 |
 
 ## リストパネルのナビゲーション
 

docs/keybindings/Keybindings_ko.md

@@ -30,9 +30,10 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` W `` | Diff 메뉴 열기 | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` <c-e> `` | Diff 메뉴 열기 | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` q `` | 종료 |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | 공백문자를 Diff 뷰에서 표시 여부 전환 | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | 되돌리기 (reflog) (실험적) | The reflog will be used to determine what git command to run to undo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
-| `` <c-z> `` | 다시 실행 (reflog) (실험적) | The reflog will be used to determine what git command to run to redo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
+| `` Z `` | 다시 실행 (reflog) (실험적) | The reflog will be used to determine what git command to run to redo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
 
 ## List panel navigation
 

docs/keybindings/Keybindings_nl.md

@@ -30,9 +30,10 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` W `` | Open diff menu | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` <c-e> `` | Open diff menu | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` q `` | Quit |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | Toggle whitespace | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | Ongedaan maken (via reflog) (experimenteel) | The reflog will be used to determine what git command to run to undo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
-| `` <c-z> `` | Redo (via reflog) (experimenteel) | The reflog will be used to determine what git command to run to redo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
+| `` Z `` | Redo (via reflog) (experimenteel) | The reflog will be used to determine what git command to run to redo the last git command. This does not include changes to the working tree; only commits are taken into consideration. |
 
 ## Lijstpaneel navigatie
 

docs/keybindings/Keybindings_pl.md

@@ -30,9 +30,10 @@ _Legenda: `<c-b>` oznacza ctrl+b, `<a-b>` oznacza alt+b, `B` oznacza shift+b_
 | `` W `` | Pokaż opcje różnicowania | Pokaż opcje dotyczące różnicowania dwóch refów, np. różnicowanie względem wybranego refa, wprowadzanie refa do różnicowania i odwracanie kierunku różnic. |
 | `` <c-e> `` | Pokaż opcje różnicowania | Pokaż opcje dotyczące różnicowania dwóch refów, np. różnicowanie względem wybranego refa, wprowadzanie refa do różnicowania i odwracanie kierunku różnic. |
 | `` q `` | Wyjdź |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | Przełącz białe znaki | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | Cofnij | Dziennik reflog zostanie użyty do określenia, jakie polecenie git należy uruchomić, aby cofnąć ostatnie polecenie git. Nie obejmuje to zmian w drzewie roboczym; brane są pod uwagę tylko commity. |
-| `` <c-z> `` | Ponów | Dziennik reflog zostanie użyty do określenia, jakie polecenie git należy uruchomić, aby ponowić ostatnie polecenie git. Nie obejmuje to zmian w drzewie roboczym; brane są pod uwagę tylko commity. |
+| `` Z `` | Ponów | Dziennik reflog zostanie użyty do określenia, jakie polecenie git należy uruchomić, aby ponowić ostatnie polecenie git. Nie obejmuje to zmian w drzewie roboczym; brane są pod uwagę tylko commity. |
 
 ## Nawigacja panelu listy
 

docs/keybindings/Keybindings_pt.md

@@ -30,9 +30,10 @@ _Legend: `<c-b>` means ctrl+b, `<a-b>` means alt+b, `B` means shift+b_
 | `` W `` | View diffing options | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` <c-e> `` | View diffing options | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` q `` | Sair |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | Toggle whitespace | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | Desfazer | O reflog será usado para determinar qual comando git para executar para desfazer o último comando git. Isto não inclui mudanças na árvore de trabalho; apenas compromissos são tidos em consideração. |
-| `` <c-z> `` | Refazer | O reflog será usado para determinar qual comando git para executar para refazer o último comando git. Isto não inclui mudanças na árvore de trabalho; apenas compromissos são tidos em consideração. |
+| `` Z `` | Refazer | O reflog será usado para determinar qual comando git para executar para refazer o último comando git. Isto não inclui mudanças na árvore de trabalho; apenas compromissos são tidos em consideração. |
 
 ## List panel navigation
 

docs/keybindings/Keybindings_ru.md

@@ -30,9 +30,10 @@ _Связки клавиш_
 | `` W `` | Открыть меню сравнении | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` <c-e> `` | Открыть меню сравнении | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` q `` | Выйти |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | Переключить отображение изменении пробелов в просмотрщике сравнении | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | Отменить (через reflog) (экспериментальный) | Журнал ссылок (reflog) будет использоваться для определения того, какую команду git запустить, чтобы отменить последнюю команду git. Сюда не входят изменения в рабочем дереве; учитываются только коммиты. |
-| `` <c-z> `` | Повторить (через reflog) (экспериментальный) | Журнал ссылок (reflog) будет использоваться для определения того, какую команду git нужно запустить, чтобы повторить последнюю команду git. Сюда не входят изменения в рабочем дереве; учитываются только коммиты. |
+| `` Z `` | Повторить (через reflog) (экспериментальный) | Журнал ссылок (reflog) будет использоваться для определения того, какую команду git нужно запустить, чтобы повторить последнюю команду git. Сюда не входят изменения в рабочем дереве; учитываются только коммиты. |
 
 ## Навигация по панели списка
 

docs/keybindings/Keybindings_zh-CN.md

@@ -30,9 +30,10 @@ _图例：`<c-b>` 意味着ctrl+b, `<a-b>意味着Alt+b, `B` 意味着shift+b_
 | `` W `` | 打开 diff 菜单 | 查看与比较两个引用相关的选项，例如与选定的 ref 进行比较，输入要比较的 ref，然后反转比较方向。 |
 | `` <c-e> `` | 打开 diff 菜单 | 查看与比较两个引用相关的选项，例如与选定的 ref 进行比较，输入要比较的 ref，然后反转比较方向。 |
 | `` q `` | 退出 |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | 切换是否在差异视图中显示空白字符差异 | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | 撤销 | Reflog将用于确定运行哪个git命令来撤消最后一个git命令。这并不包括对工作树的更改，只考虑提交。 |
-| `` <c-z> `` | 重做 | Reflog将用于确定运行哪个git命令来重做上一个git命令。这并不包括对工作树的更改，只考虑提交。 |
+| `` Z `` | 重做 | Reflog将用于确定运行哪个git命令来重做上一个git命令。这并不包括对工作树的更改，只考虑提交。 |
 
 ## 列表面板导航
 

docs/keybindings/Keybindings_zh-TW.md

@@ -30,9 +30,10 @@ _說明：`<c-b>` 表示 Ctrl＋B、`<a-b>` 表示 Alt＋B，`B`表示 Shift＋B
 | `` W `` | 開啟差異比較選單 | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` <c-e> `` | 開啟差異比較選單 | View options relating to diffing two refs e.g. diffing against selected ref, entering ref to diff against, and reversing the diff direction. |
 | `` q `` | 結束 |  |
+| `` <c-z> `` | Suspend the application |  |
 | `` <c-w> `` | 切換是否在差異檢視中顯示空格變更 | Toggle whether or not whitespace changes are shown in the diff view.<br><br>The default can be changed in the config file with the key 'git.ignoreWhitespaceInDiffView'. |
 | `` z `` | 復原 | 將使用 reflog 確任 git 指令以復原。這不包括工作區更改；只考慮提交。 |
-| `` <c-z> `` | 取消復原 | 將使用 reflog 確任 git 指令以重作。這不包括工作區更改；只考慮提交。 |
+| `` Z `` | 取消復原 | 將使用 reflog 確任 git 指令以重作。這不包括工作區更改；只考慮提交。 |
 
 ## 移動