renderer: do not render if synchronized output is on

src/renderer/Metal.zig

@@ -467,6 +467,12 @@ pub fn render(
         state.mutex.lock();
         defer state.mutex.unlock();
 
+        // If we're in a synchronized output state, we pause all rendering.
+        if (state.terminal.modes.get(.synchronized_output)) {
+            log.debug("synchronized output started, skipping render", .{});
+            return;
+        }
+
         self.cursor_visible = visible: {
             // If the cursor is explicitly not visible in the state,
             // then it is not visible.

src/renderer/OpenGL.zig

@@ -709,6 +709,12 @@ pub fn render(
         state.mutex.lock();
         defer state.mutex.unlock();
 
+        // If we're in a synchronized output state, we pause all rendering.
+        if (state.terminal.modes.get(.synchronized_output)) {
+            log.debug("synchronized output started, skipping render", .{});
+            return;
+        }
+
         self.cursor_visible = visible: {
             // If the cursor is explicitly not visible in the state,
             // then it is not visible.

src/termio/Thread.zig

@@ -29,7 +29,7 @@ const Coalesce = struct {
 
 /// The number of milliseconds before we reset the synchronized output flag
 /// if the running program hasn't already.
-const sync_reset_ms = 5000;
+const sync_reset_ms = 1000;
 
 /// Allocator used for some state
 alloc: std.mem.Allocator,