Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@electron/main.ts`:
- Around line 293-310: The close-confirm handshake can be re-entered causing
multiple pending ipcMain.once handlers; add a per-window "close confirmation in
flight" guard (e.g., a WeakMap<BrowserWindow, boolean> or a property on the
window) checked at the top of the close flow and set to true just before sending
windowToClose.webContents.send("request-close-confirm"), then clear the flag in
every terminal branch of the ipc handlers (on "close-confirm-response" for
cancel/discard, and inside the "save-before-close-done" handler whether
shouldClose is true or false) so subsequent close events are ignored until the
confirmation completes; keep references to the same event names
("close-confirm-response", "save-before-close-done") and call
forceCloseEditorWindow(windowToClose) only once after clearing the flag
appropriately.

In `@src/components/video-editor/UnsavedChangesDialog.tsx`:
- Around line 22-76: UnsavedChangesDialog is rendering a hand-rolled modal that
lacks the shared Dialog semantics (focus trap, Escape handling, accessible
names)—replace the outer fragments and fixed divs with the app's Dialog
primitive used in VideoEditor.tsx, wiring Dialog's open/onOpenChange (or
onClose) to the existing onCancel handler so Escape and backdrop clicks call
onCancel, move the title/description into Dialog.Title/Description (or the
primitive's equivalents) using td("unsavedChanges.title") and
td("unsavedChanges.message")/td("unsavedChanges.detail"), ensure the icon-only
close button (X) has an accessible name (aria-label or use Dialog.Close) and
keep the existing action buttons calling onSaveAndClose and onDiscardAndClose;
preserve styling/classes but remove the custom focus/escape logic in favor of
the Dialog primitive for proper a11y and focus trapping.

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@electron/main.ts`:
- Around line 298-305: The IPC handlers for "close-confirm-response" and
"save-before-close-done" are currently using ipcMain.once and will consume the
first matching message from any renderer, so scope them to the originating
window by switching to named listeners that check event.sender.id against
windowToClose.webContents.id and only act when they match; implement
ipcMain.on("close-confirm-response", handler) and
ipcMain.on("save-before-close-done", handler) where each handler does if
(!windowToClose || windowToClose.isDestroyed()) { cleanup/remove listener } else
if (event.sender.id !== windowToClose.webContents.id) return; else perform the
existing logic (set isCloseConfirmInFlight, send "request-save-before-close",
handle shouldClose) and remove the listener after handling to avoid leaks.
Ensure you reference the existing variables windowToClose and
isCloseConfirmInFlight and remove the listener if the window is closed or after
a successful match.

---

Duplicate comments:
In `@electron/main.ts`:
- Around line 298-307: The guard isCloseConfirmInFlight is currently cleared
immediately in the close-confirm-response handler allowing a second close to
re-enter while the save flow is in-flight; move or defer clearing that flag so
it remains true until the entire save/close flow completes: remove the early
isCloseConfirmInFlight = false at the top of the
ipcMain.once("close-confirm-response", ...) handler and instead clear
isCloseConfirmInFlight only inside each terminal branch of the flow (after
forceCloseEditorWindow when choice === "save" and after handling
discard/cancel), and also clear it inside the
ipcMain.once("save-before-close-done", ...) callback after handling shouldClose
to ensure the flag covers the full save-before-close lifetime; reference:
isCloseConfirmInFlight, ipcMain.once("close-confirm-response"),
ipcMain.once("save-before-close-done"), windowToClose, forceCloseEditorWindow.