[joshuatowner]

Expose poll interval parameter on all trainers

Adds a poll parameter to train() on SFTTrainer, DPOTrainer, RLVRTrainer, and RLAIFTrainer, allowing callers to control how frequently the SDK polls for training job status updates.

Problem

The trainer_wait.wait() function already accepts a poll parameter (default 5s), but there was no way to configure it from the trainer API. Users running in agent/script contexts want longer intervals (e.g., 30s) to reduce output noise and API calls.

Changes

• Add poll: int = 5 parameter to train() on all 4 trainers
• Pass through to trainer_wait.wait() via wait_kwargs
• Add docstring for the new parameter

# Before: no way to control poll interval
trainer.train(wait=True)

# After: configurable
trainer.train(wait=True, poll=30)

Testing

• 93 existing trainer unit tests pass (assertions updated to include poll=5)
• Manually validated with SFT and RLAIF jobs showing correct 10s intervals