style: dark theme for docs matching landing page

- Black background (#0a1a0f), white/grey text, subtle green accent
- Force dark-only mode (no light theme toggle)
- Navbar with blur backdrop, subtle borders
- Sidebar: grey text, white active, minimal hover
- Tables/code blocks: near-invisible backgrounds
- Cards: 2% white opacity, no acid colors
- Links: #00CC66 (subdued), hover: #00FF88
- Matches landing page palette exactly

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: gHashTag

docsite/docusaurus.config.ts

@@ -47,7 +47,8 @@ const config: Config = {
     image: 'img/trinity-social-card.png',
     colorMode: {
       defaultMode: 'dark',
-      respectPrefersColorScheme: true,
+      disableSwitch: true,
+      respectPrefersColorScheme: false,
     },
     navbar: {
       title: 'Trinity',