fix(desktop): external gateway mode and start script alignment

- Add desktop env for non-embedded gateway (OCLAW_DESKTOP_EMBED_BACKEND, base URL, skip channel).
- Wire start_all/start_desktop to pass gateway URL when keeping existing gateway; fix root start_all flags.
- Prefer electron.cmd for background desktop launch; admin static theme presets and chat boot timeouts.

Co-authored-by: Cursor <cursoragent@cursor.com>

scripts/start_all.ps1

@@ -3,10 +3,12 @@ param(
     [int]$Port = 8787,
     [switch]$SkipInstall = $false,
     [switch]$Background = $false,
-    [switch]$WithWeixin = $false,
+    [switch]$WithoutWeixin = $false,
+    [switch]$WithoutWhatsApp = $false,
     [bool]$WithWikiWorker = $true,
     [string]$WeixinChannelId = "oclaw-weixin",
-    [string]$WeixinGatewayBaseUrl = ""
+    [string]$WeixinGatewayBaseUrl = "",
+    [string]$WhatsAppChannelId = "whatsapp"
 )
 
 $ErrorActionPreference = "Stop"
@@ -16,5 +18,14 @@ if (-not (Test-Path $real)) {
     throw "Forward script target not found: $real"
 }
 
-& $real -BindHost $BindHost -Port $Port -SkipInstall:$SkipInstall -Background:$Background -WithWeixin:$WithWeixin -WithWikiWorker:$WithWikiWorker -WeixinChannelId $WeixinChannelId -WeixinGatewayBaseUrl $WeixinGatewayBaseUrl
-
+& $real `
+    -BindHost $BindHost `
+    -Port $Port `
+    -SkipInstall:$SkipInstall `
+    -Background:$Background `
+    -WithoutWeixin:$WithoutWeixin `
+    -WithoutWhatsApp:$WithoutWhatsApp `
+    -WithWikiWorker:$WithWikiWorker `
+    -WeixinChannelId $WeixinChannelId `
+    -WeixinGatewayBaseUrl $WeixinGatewayBaseUrl `
+    -WhatsAppChannelId $WhatsAppChannelId