Normalize ROS launch typing

[ethayu]

Summary

• Annotate the payload launch parameter list so mixed config-file and override entries keep the intended launch shape.
• Widen the sim launch Gazebo environment map to the Launch API substitution shape expected by Pyright.

Verification

• source /opt/ros/humble/setup.bash && source /home/ubuntu/monorepo/controls/sae_2025_ws/install/setup.bash && export PYTHONPATH=$PWD/controls/sae_2025_ws/src/sim:$PWD/controls/sae_2025_ws/src/payload:$PYTHONPATH && npx --yes pyright controls/sae_2025_ws/src/sim/launch/sim.launch.py controls/sae_2025_ws/src/payload/launch/payload.launch.py --outputjson
• python3 -m compileall controls/sae_2025_ws/src/sim/launch/sim.launch.py controls/sae_2025_ws/src/payload/launch/payload.launch.py
• ruff check controls/sae_2025_ws/src/sim/launch/sim.launch.py controls/sae_2025_ws/src/payload/launch/payload.launch.py
• ruff format --check controls/sae_2025_ws/src/sim/launch/sim.launch.py controls/sae_2025_ws/src/payload/launch/payload.launch.py

Refs #214
Part of #201

[ethayu]

Folded into #217 as a separate commit; closing to keep sim/payload support typing in one PR.