feat: DE summary table & volcano protein searching and labeling

[cliandouble08]

Summary

• Adds a differential expression summary table to the Statistics Summary tab showing DE feature counts per comparison (issue Export statistics summary (# of DE features) for each comparison #66)
• Adds protein search, POI labeling, and interactive volcano plots to the Statistics Plot tab (issue Searching and labeling proteins on Volcano plots #57)

Changes

New files:

• tests/testthat/test-volcano-labeling.R — unit tests for volcano search/labeling helpers

Modified files:

• R/tab_stat_summary.R — DE summary table with export support
• R/tab_stat_plot.R — protein search input, POI checkbox, interactive plotly volcano
• R/tab_stat_plot_helpers.R — get_volcano_cols, build_volcano_df, parse_protein_search_input, label/annotation helpers
• R/tab_export.R — improved export notification UX (only shows error list when errors exist)

Dependencies added: ggrepel, plotly functions (add_annotations, event_data, event_register, layout)

Minor Updates (Chore)

• Simplifies the notification for successful export to only show failed exports
• Update ggplot2 linewidth call to avoid syntax warnings

Test plan

• Load a dataset, go to Statistics Summary tab and verify DE summary table renders and can be exported
• Go to Statistics Plot tab, search for a protein by name and verify it gets highlighted/labeled on the volcano
• Toggle POI checkbox and verify label behavior
• Hover over points on the interactive volcano and verify tooltips work
• Verify devtools::test() passes including new volcano labeling tests
• Run devtools::check() with no new errors/warnings

Closes #57, Closes #66

[nmclark2]

I merged my branch into this which adds the additional improvements:

• Filter samples (columns) by a selected cdesc annotation (e.g. QC.status)
• Filter features (rows) by a selected rdesc annotation (e.g. Species)
• Implement mapping from protein IDs to gene symbols
• Fixes some bugs with the multiome heatmap, original GCT having some rdesc changes, and saving gene symbol column settings when returning to setup.