docs: restructure website, optimize HTML, gitignore private files

Website docs (website/docs/):
- Delete 6 stale -md.html duplicates
- Rename docs-clients/miners/developers → clients/miners/developers.html
- Unify header/nav across all 15 pages (new .site-header pattern)
- Fix 34 dead href=# links with real targets
- Upgrade Font Awesome v4→v6 in index.html
- Replace search stub with live client-side search (15-page index)
- Extract all inline CSS into shared docs.css (+630 lines)
- Extract inline theme JS into shared theme.js
- Strip inline style= attributes from 10+ pages
- Add .announce-banner, .source-links, .search-results CSS classes
- Add Markdown Source links to clients/miners/developers pages
- Update components.html title to Architecture & Components
- Move browser-wallet.html to website/wallet/, leave redirect
- Update all dates to February 2026

Website root:
- Delete 6 root-level duplicate HTML files (160KB saved)
- Rewire index.html and 404.html links

Root README.md:
- Fix 8 broken doc links to new numbered folder structure
- Update copyright to 2026

.gitignore + .example files:
- Gitignore private files: .aitbc.yaml, .env, deploy scripts,
  GPU scripts, service scripts, infra configs, .windsurf/, website README
- Create 7 .example files for GitHub users with sanitized templates
- Untrack 47 previously committed private files

Live server:
- Push all website files to aitbc-cascade:/var/www/html/
- Clean stale admin.html and index.nginx-debian.html

scripts/deploy/deploy-remote-build.sh

@@ -1,18 +0,0 @@
-#!/bin/bash
-
-# Deploy blockchain node by building directly on ns3 server
-
-echo "🚀 Remote Blockchain Deployment (Build on Server)"
-echo "=============================================="
-
-# Copy deployment script to server
-echo "Copying deployment script to ns3..."
-scp scripts/deploy/deploy-blockchain-remote.sh ns3-root:/opt/
-
-# Execute deployment on server
-echo "Executing deployment on ns3 (utilizing gigabit connection)..."
-ssh ns3-root "cd /opt && chmod +x deploy-blockchain-remote.sh && ./deploy-blockchain-remote.sh"
-
-echo ""
-echo "Deployment complete!"
-echo "The blockchain node was built directly on ns3 using its fast connection."