Companion to the `main` fix for huggingface/optimum-executorch#28.
Sets `bos_token_id=1, eos_token_id=2` in `config.json` and `generation_config.json`, and regenerates `model.pte` from the corrected config so its `get_bos_id`/`get_eos_id` metadata match the tokenizer.
Verified with optimum-executorch main (44fa1d3), transformers 5.0.0rc1, executorch 1.3.1:
- current `executorch` revision: `ValueError: The tokenizer's bos_token_id=1 must be the same as the model's bos_token_id=0.`
- this PR: model reports bos=1, eos=[2]; `text_generation` runs.
Export command: `optimum-cli export executorch --model <fixed main> --task text-generation --recipe xnnpack`. Note: the new `model.pte` is 4.2 MB vs 8.4 MB for the current one, likely different export defaults from when it was first made; happy to re-export with specific flags if you'd prefer.
