Fix double authentication and Matrix-Signal bridge issues

Authentication fixes:
- Removed auth.js from all HTML pages (was causing double prompts)
- Removed .htaccess and .htpasswd files (redundant with Caddy)
- Now using only Caddy basic auth: langmem / langmem2025

Signal bridge fixes:
- Found Signal bridge bot: @signalbot:matrix.klas.chat
- Created DM room between Claude user and bridge bot
- Sent login command to register Claude with Signal bridge
- Claude should now be able to bridge messages to Signal

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

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

docs/implementation/index.html

@@ -6,7 +6,6 @@
     <title>Implementation Guide - LangMem Documentation</title>
     <meta name="description" content="Step-by-step implementation guide for building the LangMem long-term memory system with detailed phases and instructions.">
     <link rel="stylesheet" href="../assets/css/style.css">
-    <script src="../auth.js"></script>
     <script src="https://cdn.jsdelivr.net/npm/mermaid/dist/mermaid.min.js"></script>
     <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/components/prism-core.min.js"></script>
     <script src="https://cdn.jsdelivr.net/npm/prismjs@1.29.0/plugins/autoloader/prism-autoloader.min.js"></script>