Add memory-viewer from silicondawn

- Web UI for browsing and editing OpenClaw memory files
- Cloned from https://github.com/silicondawn/memory-viewer
- Built and running on port 8901
- Features: file tree, markdown rendering, search, live reload
- Full access to MEMORY.md, daily notes, skills, automations

memory-viewer/.gitignore

@@ -0,0 +1,27 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules/
+dist/
+dist-ssr/
+*.local
+.env
+.env.*
+server.log
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?