* [LLaDA2] address review findings from huggingface#13598

Fixes the six in-scope issues raised in the llada2 model/pipeline review:

1. Carry tokenizer `attention_mask` through `_prepare_input_ids` and add an
   `attention_mask` arg to `__call__` for pre-tokenized inputs. The runtime
   mask now reflects prompt padding and zeros out the block-aligned tail
   past `prompt_length + gen_length` instead of treating those positions
   as valid context.

2. Thread the per-call `block_length` into `BlockRefinementScheduler.set_timesteps`
   so the transfer schedule matches the requested block size (previously the
   scheduler only read its constructor default).

3. Drop `x0`/`x0_p`/`confidence` from `_callback_tensor_inputs` (never bound
   locals) and bind `sampled_tokens`, `sampled_probs`, `editing_transfer_index`,
   `active_block` so all advertised callback keys resolve.

4. Allow EOS exactly at index `prompt_length` (the first generated position)
   to mark a row finished.

5. Freeze rows that have already emitted EOS so subsequent block refinement
   doesn't extend them, and trim per-row at decode (previously gated on
   batch_size==1) so post-EOS positions don't leak into decoded text.

6. Stop calling `self.set_progress_bar_config(...)` from inside `__call__`;
   build a local config dict for the inner block bar so user-supplied flags
   (in particular `disable=True`) survive the call.

Adds regression tests pinning each of the six fixes.

* fix formatting

* undo changes

* set block_length to optional and use scheduler's default

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Co-authored-by: dg845 <58458699+dg845@users.noreply.github.com>