feat(examples): add minimal Tensor Parallelism training example with …
Author: RithwikSharma
Pull request: yes
Labels: name: Code agent slop

…Trainer (#41141)

Adds examples/pytorch/tensor_parallelism/tp_training.py, a focused, runnable example of TP-only training using Trainer.

Key points:
- Load model with tp_plan='auto' (the only TP-specific flag needed)
- Trainer auto-detects model.tp_size and creates ParallelismConfig
- Uses SmolLM2-1.7B + TinyStories for low-resource reproducibility
- Explains common pitfalls: device_map='auto', init_empty_weights()
- Shows explicit ParallelismConfig usage as a comment for 3D parallelism

Fixes #41141

# What does this PR do?

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Fixes # (issue)

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## CI Security Gate — automatic approval blocked

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