Improve experimental data header/column parsing and make header dialog UI responsive

[KWWyatt]

Motivation

• Improve robustness when loading experimental data files by ignoring metadata/comment lines and more reliably detecting header rows and column labels.
• Make the experimental-data header dialog more usable on different screen sizes and for long file paths by adding wrapping and responsive sizing.

Description

• Enhance parsing logic in project.py by adding _strip_comment_prefix, _is_comment_metadata_line, and _tokens_look_like_column_labels helpers and updating _guess_experimental_header_rows, _read_experimental_column_names, and _first_data_tokens to skip or interpret comment/metadata lines correctly.
• Refine token classification so comment lines with metadata (e.g. # Background: ...) are not mistaken for column header lines and column label detection is improved (keywords matching and normalization).
• Update experimental_data_loader.py UI: use QApplication.primaryScreen() to bound dialog size, set better defaults for resize and maximum size, enable word wrap for file and status labels, change preview wrapping and minimum height, and add _configure_column_combo to improve QComboBox sizing behavior.
• Update test imports and add tests to cover the new behavior: test_experimental_data_header_dialog_geometry_is_screen_bounded and test_experimental_data_metadata_comments_are_not_used_as_columns.

Testing

• Ran test suite (pytest) including new UI and parser tests; test_experimental_data_header_dialog_geometry_is_screen_bounded passed.
• Ran test_experimental_data_metadata_comments_are_not_used_as_columns which verifies header detection and load_experimental_data_file behavior and passed.
• Existing experimental-data header selection tests (e.g. test_experimental_data_header_dialog_allows_manual_column_selection) were executed and remained green.

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Codex Task