core: add 'command finished' notifications

Fixes #8991

Uses OSC 133 esc sequences to keep track of how long commands take to
execute. If the user chooses, commands that take longer than a user
specified limit will trigger a notification. The user can choose between
a bell notification or a desktop notification.

src/apprt/action.zig

@@ -295,6 +295,9 @@ pub const Action = union(Key) {
     /// Show the on-screen keyboard.
     show_on_screen_keyboard,
 
+    /// A command has finished,
+    command_finished: CommandFinished,
+
     /// Sync with: ghostty_action_tag_e
     pub const Key = enum(c_int) {
         quit,
@@ -350,6 +353,7 @@ pub const Action = union(Key) {
         show_child_exited,
         progress_report,
         show_on_screen_keyboard,
+        command_finished,
     };
 
     /// Sync with: ghostty_action_u
@@ -741,3 +745,21 @@ pub const CloseTabMode = enum(c_int) {
     /// Close all other tabs.
     other,
 };
+
+pub const CommandFinished = struct {
+    exit_code: ?u8,
+    duration: configpkg.Config.Duration,
+
+    /// sync with ghostty_action_command_finished_s in ghostty.h
+    pub const C = extern struct {
+        exit_code: i16,
+        duration: u64,
+    };
+
+    pub fn cval(self: CommandFinished) C {
+        return .{
+            .exit_code = self.exit_code orelse -1,
+            .duration = self.duration.duration,
+        };
+    }
+};