feat(app): make the New tab launcher keyboard-first

Cmd/Ctrl+T now opens the focused pane's launcher, while explicit target shortcuts bypass the menu. Dispatcher ownership is scoped to the app tree so retained workspaces cannot intercept commands.

packages/app/src/i18n/resources/en.ts

@@ -590,6 +590,8 @@ export const en = {
         preparingTerminal: "Preparing terminal tab",
         preparingTerminalTooltip: "Preparing terminal...",
         newBrowser: "New browser",
+        maximizePane: "Maximize pane",
+        restorePane: "Restore pane",
         exitFocusMode: "Exit focus mode",
         splitRight: "Split pane right",
         splitDown: "Split pane down",
@@ -1362,6 +1364,7 @@ export const en = {
     openPath: "Open path",
   },
   branchSwitcher: {
+    triggerTooltip: "Switch workspace branch",
     currentBranch: "Current branch: {{branchName}}. Press to switch branch.",
     placeholder: "Switch branch...",
     searchPlaceholder: "Filter branches...",
@@ -2117,6 +2120,7 @@ export const en = {
         toggleBothSidebars: "Toggle both sidebars",
         toggleSettings: "Toggle settings",
         toggleFocusMode: "Toggle focus mode",
+        toggleExplorerPaneMaximization: "Toggle Explorer pane maximization",
         cycleTheme: "Cycle theme",
         focusMessageInput: "Focus message input",
         cycleAgentMode: "Cycle agent mode",