Refactor: Remove redundant ExecutionStateTrigger

The `ExecutionStateTrigger` struct and its associated
`executionStateTrigger` computed property in `MainContentView` are no
longer necessary. The toolbar execution state is now directly managed by
observing the `currentTab?.isExecuting` and `currentTab?.executionTime`
properties. This change simplifies the binding logic and removes
redundant state management.

Author: datlechin

TablePro/Views/Main/Extensions/MainContentView+Bindings.swift

@@ -102,14 +102,7 @@ extension MainContentView {
         )
     }
 
-    /// Trigger for toolbar execution state — combines `isExecuting` and `executionTime`
-    /// from the current tab. Replaces two separate handlers that both updated `toolbarState`.
-    var executionStateTrigger: ExecutionStateTrigger {
-        ExecutionStateTrigger(
-            isExecuting: currentTab?.isExecuting ?? false,
-            executionTime: currentTab?.executionTime
-        )
-    }
+
 }
 
 // MARK: - Equatable Trigger Types
@@ -130,9 +123,4 @@ struct PendingChangeTrigger: Equatable {
     let hasStructureChanges: Bool
 }
 
-/// Lightweight equatable value combining execution state properties
-/// for consolidated toolbar execution onChange observation.
-struct ExecutionStateTrigger: Equatable {
-    let isExecuting: Bool
-    let executionTime: TimeInterval?
-}
+

TablePro/Views/MainContentView.swift

@@ -193,12 +193,7 @@ struct MainContentView: View {
             .onChange(of: DatabaseManager.shared.currentSession?.status) { _, newStatus in
                 handleSessionStatusChange(newStatus)
             }
-            .onChange(of: executionStateTrigger) { _, newValue in
-                toolbarState.isExecuting = newValue.isExecuting
-                if let time = newValue.executionTime {
-                    toolbarState.lastQueryDuration = time
-                }
-            }
+
             .onChange(of: selectedTables) { _, newTables in
                 handleTableSelectionChange(from: previousSelectedTables, to: newTables)
                 previousSelectedTables = newTables