fixed recording workflow on ubuntu

ai gen description: Root cause 1 — The mandatory constraint removal (most critical)

In Electron 29+ / Chromium 116+, the old getUserMedia format with a mandatory: {} wrapper was removed. The capture worker was still using it:

video: { mandatory: { chromeMediaSource: 'desktop', ... } }  // broke in Electron 29+
This caused getUserMedia to throw in the worker, which sent a stream-error back to the main process, which fell back to the frame loop. Fix: flat constraint format with no mandatory wrapper.

Root cause 2 — Frame loop spammed getSources() every 200ms

Once the stream backend failed, the fallback frame loop called desktopCapturer.getSources() 5× per second. On Linux via the XDG portal, each getSources() call is a new permission request → dialog every few seconds. Fix: on Linux without click capture, don't fall back to the frame loop at all — just let interval/hotkey captures take individual fresh shots.

Root cause 3 — Interval/hotkey captures bypassed the stream backend

Even when the stream backend is running, sessionCapture('interval') went straight to shoot() → grab() → getSources(). Fix: non-click triggers now pull a buffered frame from the stream backend's ring buffer (sampled every 100ms), completely avoiding getSources().

Root cause 4 — Stream backend never started on Wayland

The earlier fix made recorderWanted = false on Wayland, so the stream backend never even started. Fix: recorderWanted is now true whenever stream capture is enabled (the default), regardless of whether click detection is available.

Safety net — setPermissionCheckHandler

Electron 29+ requires an explicit permission grant for display-capture in renderer windows. Added a handler that grants all permissions (safe for a fully local/offline app like StepForge).

Windows is completely unaffected — the constraint fix is Electron-version level (affects both platforms the same), and all the Linux-specific frame-loop guards only fire when clickCaptureAvailable() returns false, which only happens on Wayland.

app/main.js

@@ -5,7 +5,7 @@ const fs = require('node:fs');
 const os = require('node:os');
 const {
   app, BrowserWindow, ipcMain, dialog, shell, nativeTheme, globalShortcut,
-  clipboard, nativeImage, screen, powerSaveBlocker,
+  clipboard, nativeImage, screen, powerSaveBlocker, session,
 } = require('electron');
 
 const { GuideStore } = require('../core/store');
@@ -835,6 +835,15 @@ if (!gotLock) {
       textIntel,
     });
 
+    // Allow the hidden capture-worker renderer to open a desktop media stream
+    // via getUserMedia. Electron 29+ requires an explicit permission grant for
+    // display-capture in renderer windows; without it the getUserMedia call
+    // fails, the stream backend never starts, and every capture falls back to
+    // desktopCapturer.getSources() — which triggers the portal dialog on Linux
+    // on every single capture. StepForge is fully local/offline so allowing
+    // all permissions for our own content is safe.
+    session.defaultSession.setPermissionCheckHandler(() => true);
+
     applyTheme();
     setupIpc();
     createWindow();