Add themes selector

Downterm/CommandNotch/Models/TerminalManager.swift

@@ -13,6 +13,8 @@ class TerminalManager: ObservableObject {
 
     @AppStorage(NotchSettings.Keys.terminalFontSize)
     private var fontSize: Double = NotchSettings.Defaults.terminalFontSize
+    @AppStorage(NotchSettings.Keys.terminalTheme)
+    private var theme: String = NotchSettings.Defaults.terminalTheme
 
     private var cancellables = Set<AnyCancellable>()
 
@@ -35,7 +37,10 @@ class TerminalManager: ObservableObject {
     // MARK: - Tab operations
 
     func newTab() {
-        let session = TerminalSession(fontSize: CGFloat(fontSize))
+        let session = TerminalSession(
+            fontSize: CGFloat(fontSize),
+            theme: TerminalTheme.resolve(theme)
+        )
 
         // Forward title changes to trigger view updates in this manager
         session.$title
@@ -104,4 +109,10 @@ class TerminalManager: ObservableObject {
             tab.updateFontSize(size)
         }
     }
+
+    func updateAllThemes(_ theme: TerminalTheme) {
+        for tab in tabs {
+            tab.applyTheme(theme)
+        }
+    }
 }