Add support for Jeep Grand Cherokee SRT 2016-18

[alxs1234]

The SRT trim uses significantly different steering hardware/ratio than the standard Grand Cherokee, requiring a separate platform entry.

Key differences from JEEP_GRAND_CHEROKEE:

• steerRatio: 13.0 (vs 16.7 on standard GC)
• mass: 1836 kg (vs 1778 kg)
• Older EPS firmware (68252416AL, below 6841 threshold)
• Sportier EPS benefits from higher STEER_DELTA_UP/DOWN (6 vs 3)

Changes:

• values.py: Add JEEP_GRAND_CHEROKEE_SRT_2016 platform and SRT_CARS set with tuned CarControllerParams (STEER_DELTA_UP/DOWN=6, STEER_MAX=261)
• fingerprints.py: Add 7 ECU firmware versions
• interface.py: Add SRT to Jeep Grand Cherokee elif branch
• params.toml: Add torque params (copied from GC, measured data to follow)

Tested on: 2016 Jeep Grand Cherokee SRT (VIN: 1C4RJFDJ3GC420967)
Hardware: comma 4, FCA harness
FFCM: 68251681AF (factory installed, LaneSense enabled via BCM config)

Validation:

• Dongle ID: 0d229e810a3e34c5
• Route: 0d229e810a3e34c5/0000000d--f284666791

[github-actions]

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[github-actions]

Car behavior report

Replays driving segments through this PR and compares the behavior to master.
Please review any changes carefully to ensure they are expected.

Testing 40 segments for: CHRYSLER_PACIFICA_2018_HYBRID, CHRYSLER_PACIFICA_2019_HYBRID, CHRYSLER_PACIFICA_2018, CHRYSLER_PACIFICA_2020

✅ 0 changed, 40 passed, 0 errors

[alxs1234]

keeping PR as draft until I can work through errors I'm seeing on vehicle.