Add LFM2.5-VL-3B benchmark handling

[rshube]

Summary

• Add benchmark-specific prompting and ScreenSpot response normalization for LFM2.5-VL-3B.
• Preserve existing LFM2-VL registrations without custom prompting.
• Preserve chat roles, interleaved inputs, completion-only decoding, and deterministic generation.
• Fix MM-IFEval verifier lookup and localized image paths.

Validation

• pytest -q: 27 passed
• Python compilation and liquid.py lint passed
• ScreenSpot-v2 and MMMU-Pro scores reproduced exactly
• MMMU validation predictions reproduced exactly

[rshube]

Checkpoint reproduction for affected benchmarks

Only benchmarks with dataset-specific prompting or response handling in this PR are listed. Published values are from the release table; scores are normalized to 0–100.

Benchmark	Published	Reproduced	Delta	Handling
MME	73.1	73.89	+0.79	Category-specific answer formats
SimpleVQA	35.4	35.67	+0.27	No appended instruction
MM-IFEval	60.6	59.04	-1.56	Preserve image-first ordering; judge-dependent score
LogicVista	37.4	37.58	+0.18	No appended instruction
MathVista (mini)	68.5	68.50	0.00	Step-by-step reasoning with boxed final answer
MMMU (validation)	48.4	48.22	-0.18	No appended instruction
OCRBench v1	84.2	84.10	-0.10	Concise-answer instruction
BLINK	61.5	61.55	+0.05	No redundant instruction
MUIRBench	58.3	58.27	-0.03	Numbered images and explicit final option format
HallusionBench	47.2	47.25	+0.05	Yes/no instruction; judge-dependent score
POPE	88.7	88.75	+0.05	No appended instruction
RefCOCO average	87.9	88.86	+0.96	Strict normalized bounding-box JSON
ScreenSpot-v2 Desktop	78.7	78.44	-0.26	Click-target prompt and response normalization
ScreenSpot-v2 Mobile	81.2	80.64	-0.56	Click-target prompt and response normalization
ScreenSpot-v2 Web	82.2	82.15	-0.05	Click-target prompt and response normalization