robotiq_tsf: tsf_driver.launch.py defaults to an executable the package does not install

[ebarnett3]

tsf_driver.launch.py declares its poller argument with default_value="poll_data_node":

poller_arg = DeclareLaunchArgument(
    "poller",
    default_value="poll_data_node",
    description="Driver executable publishing StaticData. Override to "
    "point the viz at an alternative poller.",
)

robotiq_tsf installs poll_data_sdk_node and tactile_total_sum_node, and no poll_data_node. So the documented command fails:

ros2 launch robotiq_tsf tsf_driver.launch.py     # executable not found
ros2 launch robotiq_tsf tsf_driver.launch.py poller:=poll_data_sdk_node   # works

Found while bringing the sensor up for an MCP bench session on 2026-09-11. Pre-existing, unrelated to any open PR.

tactile_viz.launch.py and gripper_tactile_viz.launch.py include this file and carry the same default, so they fail the same way unless the argument is passed.

Fix

Default to poll_data_sdk_node, the executable the package installs. Worth a test that the default names something in the package's install space, since the failure is a runtime "executable not found" that no build catches.