feat: web login system, auto-load history, config extraction

- Add Flask session-based authentication (username/password login)
- Auto-load chat history from backend on page load
- Extract SECRET_KEY and user credentials to web_config.json
- Create web_config.example.json as template
- Add web_config.json to .gitignore (sensitive info)
- Update docs: architecture, API reference, quick start guides

docs/en/quick_start.md

@@ -40,6 +40,26 @@ TrulyMEM.exe
 
 Config will be automatically saved to `~/.trulymem/config.json` and loaded on next startup.
 
+### Web Visualization (Optional)
+
+TrulyMEM provides a Web star-map visualization interface for browsing the knowledge graph in real-time:
+
+```bash
+# Start Web service
+python web_api.py --port 4096
+```
+
+Then open `http://localhost:4096` in your browser.
+
+**Login Setup:**
+1. Copy `web_config.example.json` to `web_config.json`
+2. Set login password (using SHA256) and secret key
+3. Web service will automatically read the config
+
+Default port is 4096, change with `--port` flag.
+
+---
+
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