Support Qwen3-VL-4B with hidden states extraction and compression script

[WhXcjm]

Introduce functionality to extract hidden states from decoder layer outputs and add a new compression script for Qwen3-VL-4B.

[Copilot]

Pull request overview

This PR adds support for extracting decoder hidden states across different decoder-layer output formats (needed for Qwen3-VL-4B), and introduces a new convenience script for compressing/evaluating Qwen3-VL-4B.

Changes:

• Add a shared helper to consistently extract hidden states from decoder layer outputs during calibration/block search.
• Update block forward paths to use the new hidden-state extraction helper instead of assuming tuple outputs.
• Add a Qwen3-VL-4B compression shell script and ignore a new submissions/ output folder.

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 1 comment.

File	Description
scripts/compress_qwen3vl4b_jsq_hessian.sh	Adds a runnable script for compressing Qwen3-VL-4B with JSQ settings and running lmms-eval tasks.
jsq/compression/collector.py	Adds _extract_hidden_states() and uses it when running decoder blocks to get correct hidden states across output formats.
jsq/compression/block_search.py	Uses _extract_hidden_states() in the lightweight forward path during MA-JSQ block search.
.gitignore	Ignores submissions/ directory.

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[WhXcjm]

@copilot review current codes