fix: remount terminal panes after shutdown to restore PTY connections (#73)

When all PTYs are dead after shutdown, bump a generation counter on
terminal tabs so React remounts TerminalPane components with fresh
PTY connections instead of showing stale terminals.

Also converts interfaces to type aliases in types.ts to satisfy linter.

Co-authored-by: Claude Opus 4.6 <noreply@anthropic.com>

src/renderer/src/components/Terminal.tsx

@@ -386,7 +386,7 @@ export default function Terminal(): React.JSX.Element | null {
               >
                 {worktreeTabs.map((tab) => (
                   <TerminalPane
-                    key={tab.id}
+                    key={`${tab.id}-${tab.generation ?? 0}`}
                     tabId={tab.id}
                     worktreeId={worktree.id}
                     cwd={worktree.path}

src/renderer/src/store/slices/worktrees.ts

@@ -235,6 +235,24 @@ export const createWorktreeSlice: StateCreator<AppState, [], [], WorktreeSlice>
       }
     })
 
+    // If the worktree has tabs but all PTYs are dead (e.g. after shutdown),
+    // bump generation so TerminalPanes remount with fresh PTY connections.
+    if (worktreeId) {
+      const tabs = get().tabsByWorktree[worktreeId] ?? []
+      const allDead = tabs.length > 0 && tabs.every((tab) => !tab.ptyId)
+      if (allDead) {
+        set((s) => ({
+          tabsByWorktree: {
+            ...s.tabsByWorktree,
+            [worktreeId]: (s.tabsByWorktree[worktreeId] ?? []).map((tab) => ({
+              ...tab,
+              generation: (tab.generation ?? 0) + 1
+            }))
+          }
+        }))
+      }
+    }
+
     // Refresh GitHub data (PR + issue status) when switching to a different worktree
     if (worktreeId && worktreeId !== prevActiveId) {
       get().refreshGitHubForWorktree(worktreeId)