fix: add SGR 221/222 kitty bold/faint individual reset

Handle SGR 221 (reset bold only) and SGR 222 (reset faint/dim only)
as kitty terminal extensions. Standard SGR 22 resets both simultaneously;
these codes allow independent control.

Fixes #32

Co-authored-by: Ona <no-reply@ona.com>

Author: ona-automations

inputhandler_sgr.go

@@ -145,6 +145,14 @@ func (h *InputHandler) charAttributes(params *Params) bool {
 			attr.Extended = attr.extended().Clone()
 			attr.Extended.SetUnderlineColor(0)
 			attr.UpdateExtended()
+
+		case p == 221:
+			// kitty extension: reset bold only (leaves faint intact)
+			attr.Fg &^= FgFlagBold
+
+		case p == 222:
+			// kitty extension: reset faint/dim only (leaves bold intact)
+			attr.Bg &^= BgFlagDim
 		}
 	}
 	return true

inputhandler_sgr_test.go

@@ -547,3 +547,4 @@ func TestSGR_MultipleResets(t *testing.T) {
 		t.Errorf("bg not reset: got %08x, want %08x", h.curAttrData.Bg&bgMask, def.Bg&bgMask)
 	}
 }
+