Polish Foundry desktop UI: billing redesign, sidebar hover menu, org switching fix

- Redesign billing page with task-hours pricing model (Free: 8h, Pro: 200h/seat)
- Add bulk hour purchase packages and Stripe payment management
- Remove Usage nav section, add upgrade CTA in Members for free plan
- Fix gear icon to open menu on hover with debounced timers
- Fix org switching in workspace flyout (portal outside-click detection)
- Fix tab strip padding when sidebar is collapsed
- Update website components and Tauri config

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

frontend/packages/website/src/layouts/Layout.astro

@@ -40,7 +40,7 @@ const structuredData = {
     <meta name="keywords" content="coding agents, AI SDK, Claude Code, Codex, OpenCode, Amp, Pi, sandbox, remote code execution, developer tools, AI coding assistant, code automation" />
     <meta name="author" content="Rivet" />
     <meta name="robots" content="index, follow" />
-    <meta name="theme-color" content="#000000" />
+    <meta name="theme-color" content="#09090b" />
     <link rel="canonical" href={canonicalURL} />
     <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
 
@@ -48,8 +48,8 @@ const structuredData = {
     <link rel="preconnect" href="https://fonts.googleapis.com" />
     <link rel="preconnect" href="https://fonts.gstatic.com" crossorigin />
 
-    <!-- Manrope + JetBrains Mono (from Google Fonts) -->
-    <link href="https://fonts.googleapis.com/css2?family=JetBrains+Mono:wght@400;500;600&family=Manrope:wght@400;500;600;700;800&display=swap" rel="stylesheet" />
+    <!-- IBM Plex Sans + IBM Plex Mono (from Google Fonts) -->
+    <link href="https://fonts.googleapis.com/css2?family=IBM+Plex+Mono:wght@400;500&family=IBM+Plex+Sans:wght@400;500;600;700&display=swap" rel="stylesheet" />
 
     <title>{title}</title>