feat(ui): add relationship management features in schema editor

- Implement functionality to create, update, delete, and view relationships between tables.
- Introduce new UI screens for managing relationships, including forms for adding and editing relationships.
- Enhance table editor with navigation to relationship management.
- Ensure relationships are displayed in a structured table format for better usability.

pkg/ui/table_screens.go

@@ -270,6 +270,9 @@ func (se *SchemaEditor) showTableEditor(schemaIndex, tableIndex int, table *mode
 			se.showColumnEditor(schemaIndex, tableIndex, row-1, column)
 		}
 	})
+	btnRelations := tview.NewButton("Relations [r]").SetSelectedFunc(func() {
+		se.showRelationshipList(schemaIndex, tableIndex)
+	})
 	btnDelTable := tview.NewButton("Delete Table [d]").SetSelectedFunc(func() {
 		se.showDeleteTableConfirm(schemaIndex, tableIndex)
 	})
@@ -308,6 +311,18 @@ func (se *SchemaEditor) showTableEditor(schemaIndex, tableIndex int, table *mode
 			se.app.SetFocus(btnEditColumn)
 			return nil
 		}
+		if event.Key() == tcell.KeyTab {
+			se.app.SetFocus(btnRelations)
+			return nil
+		}
+		return event
+	})
+
+	btnRelations.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
+		if event.Key() == tcell.KeyBacktab {
+			se.app.SetFocus(btnEditTable)
+			return nil
+		}
 		if event.Key() == tcell.KeyTab {
 			se.app.SetFocus(btnDelTable)
 			return nil
@@ -317,7 +332,7 @@ func (se *SchemaEditor) showTableEditor(schemaIndex, tableIndex int, table *mode
 
 	btnDelTable.SetInputCapture(func(event *tcell.EventKey) *tcell.EventKey {
 		if event.Key() == tcell.KeyBacktab {
-			se.app.SetFocus(btnEditTable)
+			se.app.SetFocus(btnRelations)
 			return nil
 		}
 		if event.Key() == tcell.KeyTab {
@@ -342,6 +357,7 @@ func (se *SchemaEditor) showTableEditor(schemaIndex, tableIndex int, table *mode
 	btnFlex.AddItem(btnNewCol, 0, 1, true).
 		AddItem(btnEditColumn, 0, 1, false).
 		AddItem(btnEditTable, 0, 1, false).
+		AddItem(btnRelations, 0, 1, false).
 		AddItem(btnDelTable, 0, 1, false).
 		AddItem(btnBack, 0, 1, false)
 
@@ -373,6 +389,10 @@ func (se *SchemaEditor) showTableEditor(schemaIndex, tableIndex int, table *mode
 			}
 			return nil
 		}
+		if event.Rune() == 'r' {
+			se.showRelationshipList(schemaIndex, tableIndex)
+			return nil
+		}
 		if event.Rune() == 'b' {
 			se.pages.RemovePage("table-editor")
 			se.pages.SwitchToPage("schema-editor")