fix(desktop): disable GPU acceleration on remote displays to stop flicker

Users on remote/forwarded displays (SSH X11 forwarding, VNC, RDP, WSLg)
reported the window flickering during scroll/streaming; nobody on native
Windows/macOS ever saw it.

Root cause: the app shipped with Chromium's default GPU hardware
acceleration and no remote-display handling. Over a remote connection the
GPU compositor can't present accelerated layers cleanly across the wire,
so the surface flashes on repaint. Local sessions composite on the GPU
and never hit it.

Detect a remote display before app `ready` (detectRemoteDisplay in
bootstrap-platform.cjs) and fall back to software rendering via
app.disableHardwareAcceleration() + --disable-gpu-compositing. Software
compositing is rock-steady over the wire and the CPU cost is negligible
next to the connection's latency. HERMES_DESKTOP_DISABLE_GPU overrides
detection both ways for VNC/screen-sharing setups we can't sniff or
remote hosts that do have working acceleration.

apps/desktop/electron/bootstrap-platform.test.cjs

@@ -3,7 +3,12 @@ const fs = require('node:fs')
 const path = require('node:path')
 const test = require('node:test')
 
-const { bundledRuntimeImportCheck, isWindowsBinaryPathInWsl, isWslEnvironment } = require('./bootstrap-platform.cjs')
+const {
+  bundledRuntimeImportCheck,
+  detectRemoteDisplay,
+  isWindowsBinaryPathInWsl,
+  isWslEnvironment
+} = require('./bootstrap-platform.cjs')
 
 test('isWslEnvironment detects WSL2 env vars on linux', () => {
   assert.equal(isWslEnvironment({ WSL_DISTRO_NAME: 'Ubuntu' }, 'linux'), true)
@@ -28,6 +33,56 @@ test('bundledRuntimeImportCheck selects platform-specific import checks', () =>
   assert.equal(bundledRuntimeImportCheck('linux'), 'import fastapi, uvicorn, ptyprocess')
 })
 
+test('detectRemoteDisplay keeps GPU on for local sessions', () => {
+  // Plain local X11, Wayland, native Windows, native macOS — no remote signal.
+  assert.equal(detectRemoteDisplay({ env: { DISPLAY: ':0' }, platform: 'linux', isWsl: false }), null)
+  assert.equal(detectRemoteDisplay({ env: { WAYLAND_DISPLAY: 'wayland-0' }, platform: 'linux', isWsl: false }), null)
+  assert.equal(detectRemoteDisplay({ env: { SESSIONNAME: 'Console' }, platform: 'win32' }), null)
+  assert.equal(detectRemoteDisplay({ env: {}, platform: 'darwin' }), null)
+})
+
+test('detectRemoteDisplay flags SSH sessions on any platform', () => {
+  assert.equal(detectRemoteDisplay({ env: { SSH_CONNECTION: '1.2.3.4 5 6.7.8.9 22' }, platform: 'linux' }), 'ssh-session')
+  assert.equal(detectRemoteDisplay({ env: { SSH_CLIENT: '1.2.3.4 5 22' }, platform: 'darwin' }), 'ssh-session')
+  assert.equal(detectRemoteDisplay({ env: { SSH_TTY: '/dev/pts/0' }, platform: 'win32' }), 'ssh-session')
+})
+
+test('detectRemoteDisplay flags forwarded X11 displays but not local ones', () => {
+  assert.match(
+    String(detectRemoteDisplay({ env: { DISPLAY: 'localhost:10.0' }, platform: 'linux', isWsl: false })),
+    /x11-forwarding/
+  )
+  assert.match(
+    String(detectRemoteDisplay({ env: { DISPLAY: '192.168.1.5:0' }, platform: 'linux', isWsl: false })),
+    /x11-forwarding/
+  )
+  assert.equal(detectRemoteDisplay({ env: { DISPLAY: ':1' }, platform: 'linux', isWsl: false }), null)
+})
+
+test('detectRemoteDisplay flags WSLg and RDP', () => {
+  assert.equal(detectRemoteDisplay({ env: { DISPLAY: ':0' }, platform: 'linux', isWsl: true }), 'wslg')
+  assert.match(
+    String(detectRemoteDisplay({ env: { SESSIONNAME: 'RDP-Tcp#7' }, platform: 'win32' })),
+    /^rdp/
+  )
+})
+
+test('detectRemoteDisplay honors the HERMES_DESKTOP_DISABLE_GPU override both ways', () => {
+  // Force-on even on a local display.
+  assert.match(
+    String(detectRemoteDisplay({ env: { HERMES_DESKTOP_DISABLE_GPU: '1', DISPLAY: ':0' }, platform: 'linux', isWsl: false })),
+    /override/
+  )
+  // Force-off even over SSH (escape hatch when a remote display has working accel).
+  assert.equal(
+    detectRemoteDisplay({
+      env: { HERMES_DESKTOP_DISABLE_GPU: 'false', SSH_CONNECTION: '1.2.3.4 5 6.7.8.9 22' },
+      platform: 'linux'
+    }),
+    null
+  )
+})
+
 test('packaged electron entrypoints do not require unpackaged npm modules', () => {
   const electronDir = __dirname
   const entrypoints = ['main.cjs', 'preload.cjs', 'bootstrap-platform.cjs']