Break out non-autocomplete changes from autocomplete PR (#618)

This improves the ephemeral command runner to allow for honoring of
timeouts and proper handling of overriding the current working
directory. It also fixes some partially transparent font colors in light
mode, making them solid instead. It also updates the InputModel to be
auto-observable and utilize some getters to ensure the cmdinput is
getting updated whenever necessary state changes take place.

waveshell/pkg/shexec/shexec.go

@@ -926,12 +926,11 @@ func RunCommandSimple(pk *packet.RunPacketType, sender *packet.PacketSender, fro
 		rcFileName = fmt.Sprintf("/dev/fd/%d", rcFileFdNum)
 	}
 	if cmd.TmpRcFileName != "" {
-		go func() {
+		time.AfterFunc(2*time.Second, func() {
 			// cmd.Close() will also remove rcFileName
 			// adding this to also try to proactively clean up after 2-seconds.
-			time.Sleep(2 * time.Second)
 			os.Remove(cmd.TmpRcFileName)
-		}()
+		})
 	}
 	fullCmdStr := pk.Command
 	if pk.ReturnState {
@@ -1109,6 +1108,14 @@ func RunCommandSimple(pk *packet.RunPacketType, sender *packet.PacketSender, fro
 	if err != nil {
 		return nil, err
 	}
+
+	if pk.Timeout > 0 {
+		// Cancel the command if it takes too long
+		time.AfterFunc(pk.Timeout, func() {
+			cmd.Cmd.Cancel()
+			cmd.Close()
+		})
+	}
 	return cmd, nil
 }