fix(site): use rectangular white OG card for social previews

Add og-card-white.png (1200x630) so LinkedIn shows the full logo without cropping.

Author: TamLeal

site/download.html

@@ -17,17 +17,17 @@
   <meta property="og:title" content="Download GitDock | Free, Local Git Dashboard">
   <meta property="og:description" content="Download GitDock for Windows, macOS, or Linux. Free, open-source, runs locally.">
   <meta property="og:url" content="https://www.gitdock.dev/download.html">
-  <meta property="og:image" content="https://www.gitdock.dev/gitdock-logo.png">
+  <meta property="og:image" content="https://www.gitdock.dev/og-card-white.png">
   <meta property="og:image:type" content="image/png">
-  <meta property="og:image:width" content="1024">
-  <meta property="og:image:height" content="1024">
+  <meta property="og:image:width" content="1200">
+  <meta property="og:image:height" content="630">
   <meta property="og:image:alt" content="GitDock logo">
 
   <!-- Twitter Card -->
   <meta name="twitter:card" content="summary_large_image">
   <meta name="twitter:title" content="Download GitDock | Free, Local Git Dashboard">
   <meta name="twitter:description" content="Download GitDock for Windows, macOS, or Linux. Free, open-source, runs locally.">
-  <meta name="twitter:image" content="https://www.gitdock.dev/gitdock-logo.png">
+  <meta name="twitter:image" content="https://www.gitdock.dev/og-card-white.png">
   <meta name="twitter:image:alt" content="GitDock logo">
 
   <style>

site/index.html

@@ -17,17 +17,17 @@
   <meta property="og:title" content="GitDock | Organize Git Projects, One Dashboard">
   <meta property="og:description" content="Open-source local dashboard to search, organize, and operate on all your Git repos. Clone, commit, push, pull, transfer — one interface, no cloud.">
   <meta property="og:url" content="https://www.gitdock.dev/">
-  <meta property="og:image" content="https://www.gitdock.dev/gitdock-logo.png">
+  <meta property="og:image" content="https://www.gitdock.dev/og-card-white.png">
   <meta property="og:image:type" content="image/png">
-  <meta property="og:image:width" content="1024">
-  <meta property="og:image:height" content="1024">
+  <meta property="og:image:width" content="1200">
+  <meta property="og:image:height" content="630">
   <meta property="og:image:alt" content="GitDock logo">
 
   <!-- Twitter Card -->
   <meta name="twitter:card" content="summary_large_image">
   <meta name="twitter:title" content="GitDock | Organize Git Projects, One Dashboard">
   <meta name="twitter:description" content="Open-source local dashboard to search, organize, and operate on all your Git repos. One interface, no cloud.">
-  <meta name="twitter:image" content="https://www.gitdock.dev/gitdock-logo.png">
+  <meta name="twitter:image" content="https://www.gitdock.dev/og-card-white.png">
   <meta name="twitter:image:alt" content="GitDock logo">
 
   <!-- Structured Data -->
@@ -47,7 +47,7 @@
     },
     "license": "https://www.apache.org/licenses/LICENSE-2.0",
     "downloadUrl": "https://www.gitdock.dev/download.html",
-    "screenshot": "https://www.gitdock.dev/gitdock-logo.png",
+    "screenshot": "https://www.gitdock.dev/og-card-white.png",
     "softwareHelp": "https://github.com/gitdock-dev/gitdock",
     "isAccessibleForFree": true
   }