fix(electron): theme Windows titlebar overlay (#16843)

Co-authored-by: Brendan Allan <brendonovich@outlook.com>

packages/desktop-electron/src/preload/index.ts

@@ -57,6 +57,7 @@ const api: ElectronAPI = {
   relaunch: () => ipcRenderer.send("relaunch"),
   getZoomFactor: () => ipcRenderer.invoke("get-zoom-factor"),
   setZoomFactor: (factor) => ipcRenderer.invoke("set-zoom-factor", factor),
+  setTitlebar: (theme) => ipcRenderer.invoke("set-titlebar", theme),
   loadingWindowComplete: () => ipcRenderer.send("loading-window-complete"),
   runUpdater: (alertOnFail) => ipcRenderer.invoke("run-updater", alertOnFail),
   checkUpdate: () => ipcRenderer.invoke("check-update"),

packages/desktop-electron/src/preload/types.ts

@@ -10,6 +10,9 @@ export type SqliteMigrationProgress = { type: "InProgress"; value: number } | {
 export type WslConfig = { enabled: boolean }
 
 export type LinuxDisplayBackend = "wayland" | "auto"
+export type TitlebarTheme = {
+  mode: "light" | "dark"
+}
 
 export type ElectronAPI = {
   killSidecar: () => Promise<void>
@@ -57,6 +60,7 @@ export type ElectronAPI = {
   relaunch: () => void
   getZoomFactor: () => Promise<number>
   setZoomFactor: (factor: number) => Promise<void>
+  setTitlebar: (theme: TitlebarTheme) => Promise<void>
   loadingWindowComplete: () => void
   runUpdater: (alertOnFail: boolean) => Promise<void>
   checkUpdate: () => Promise<{ updateAvailable: boolean; version?: string }>