chore: use encrypted db with default db pass

bin/chat-cli/README.md

@@ -78,6 +78,7 @@ Data is stored in the `tmp/chat-cli-data/` directory:
 | `<username>_state.json` | CLI state: username↔chat mappings, message history, active chat |
 | `transport/<username>/` | Inbox directory for receiving messages |
 
+The sqlite tables can be viewed with app `DB Browser for SQLite`, password is `123456`, config use `SQLCipher 4 defaults`.
 
 ## Example Session
 

bin/chat-cli/src/app.rs

@@ -68,7 +68,10 @@ impl ChatApp {
         // Open or create the chat manager with file-based storage
         let manager = ChatManager::new_from_store(
             user_name,
-            ChatStorage::new(StorageConfig::File(db_path.to_string_lossy().to_string()))?,
+            ChatStorage::new(StorageConfig::Encrypted {
+                path: db_path.to_string_lossy().to_string(),
+                key: "123456".to_string(),
+            })?,
         )
         .context("Failed to open ChatManager")?;