Update documentation files (README.md and claude.md) based on codebase analysis

README.md

@@ -44,6 +44,9 @@ Open http://localhost:8080 in your browser.
   - Edit existing rows.
   - Delete rows.
 - Generic, schema-agnostic behavior using `information_schema`.
+- CSV import/export functionality.
+- Database backup using mysqldump.
+- Foreign key relationship support.
 
 ---
 
@@ -75,6 +78,7 @@ project/
     Db.php             # PDO factory based on session credentials
     MetaService.php    # Schema/metadata from information_schema
     DataService.php    # Generic SELECT/INSERT/UPDATE/DELETE
+    BackupService.php  # Database backup functionality using mysqldump
 ```
 
 ---
@@ -136,7 +140,7 @@ No database name is hardcoded: the app reads available schemas from `information
 
 ## Running the App (Development)
 
-Use PHP’s built-in web server and point it to the `public` directory:
+Use PHP's built-in web server and point it to the `public` directory:
 
 ```bash
 cd /path/to/mariadb-grid
@@ -163,7 +167,7 @@ http://localhost:8080/
 3. If the connection succeeds:
    - The left sidebar will show databases and tables as a tree.
 4. Click any table:
-   - The central Tabulator grid will load the table’s data.
+   - The central Tabulator grid will load the table's data.
    - Column header filters allow you to filter per column.
    - Pagination is handled server-side.
 
@@ -181,15 +185,24 @@ http://localhost:8080/
   - Click **“Delete”**.
   - Confirm the deletion.
 
-> Updates and deletes are performed using the table’s primary key.  
+> Updates and deletes are performed using the table's primary key.
 > If there is no primary key, it is safer to treat the table as read-only.
 
+### CSV Operations
+
+- **Import CSV**: Use the import button to upload CSV files for bulk data insertion
+- **Export CSV**: Use the export button to download table data as CSV files
+
+### Backup Operations
+
+- **Database Backup**: Use the backup functionality to create database dumps using mysqldump
+
 ---
 
 ## How It Works (High Level)
 
 - On login, the app tests a connection to MariaDB using the supplied credentials and stores them in the session.
-- For all subsequent API requests, PDO is created with these credentials, so MariaDB’s own permissions control what the user can see and edit.
+- For all subsequent API requests, PDO is created with these credentials, so MariaDB's own permissions control what the user can see and edit.
 - `MetaService` queries `information_schema` to:
   - Build the schema → tables tree.
   - Load column definitions and detect the primary key.
@@ -223,4 +236,9 @@ http://localhost:8080/
   - Verify `DB_HOST` and `DB_PORT` environment variables.
   - Confirm credentials using `mysql` client or another tool.
   - Check firewall and bind-address on the MariaDB server.
-  - If running in Docker, use host IP or `host.docker.internal` instead of `localhost`.
+  - If running in Docker, use host IP or `host.docker.internal` instead of `localhost`.
+
+- **CSV import errors**
+  - Check that CSV files are properly formatted
+  - Ensure data types match the target table schema
+  - Review error messages for specific issues with rows or fields