feat: send screen recordings (#128)

* first pass implementation

* remove screenrecord shortcut hint

* refactor

* fix: prevent mirror review of screen recording

* feat: allow recording with webcam overlay

* fix: review screen recording without clipped content

* tidy keyboard hints consistent position

* refactor: re-use one component for screen picker

huddles and screen clips use same picker component now. We had to make
sure that tailwind works for both of them.

* fix: improve visibility of keyboard hints

During compose video or screen recording, the keyboard hints were
invisible if the content was super bright.

js/src/preload.ts

@@ -41,6 +41,26 @@ contextBridge.exposeInMainWorld('electronAutoplay', {
   },
 });
 
+contextBridge.exposeInMainWorld('electronScreen', {
+  getScreenSources: () => ipcRenderer.invoke('screen:get-sources'),
+  startRecordingWindow: (data: { includeCamera: boolean }) => ipcRenderer.send('screen-record:start', data),
+  stopRecordingWindow: () => ipcRenderer.send('screen-record:cancel'),
+  onStopRequested: (callback: () => void) => {
+    const handler = () => callback();
+    ipcRenderer.on('screen-record:stopped', handler);
+    return () => { ipcRenderer.removeListener('screen-record:stopped', handler); };
+  },
+});
+
+contextBridge.exposeInMainWorld('electronScreenRecord', {
+  stop: () => ipcRenderer.send('screen-record:stop'),
+  onInit: (callback: (data: { includeCamera: boolean }) => void) => {
+    const handler = (_event: Electron.IpcRendererEvent, data: { includeCamera: boolean }) => callback(data);
+    ipcRenderer.on('screen-record:init', handler);
+    return () => { ipcRenderer.removeListener('screen-record:init', handler); };
+  },
+});
+
 contextBridge.exposeInMainWorld('electronLink', {
   fetchMetadata: (url: string) => ipcRenderer.invoke('link:fetch-metadata', url),
   openExternal: (url: string) => ipcRenderer.invoke('link:open-external', url),