Implement Plotting extension

Summary

Create a modular plotting extension in QEDprobing.jl for generating 1D and 2D diagnostics from scattering event lists. The goal is to support reproducible, high-quality visualizations directly within the simulation workflow.

Tasks

1. Create QEDprobingPlots submodule

• Add directory src/QEDprobingPlots/
• Include in QEDprobing.jl under QEDprobing.Plots
• use the package extension functionality to load the plottig module, if CairoMakie is loaded.

2. Implement 1D projection plotting

• plot_1d_projection(events; quantity, unit, bins)
• Add support for: :q, :omega, :theta, :costheta, :omega'
• Enable units: :me, :eV, :keV, :invA

3. Implement 2D projection plotting

• plot_2d_projection(events; x, y, xunit, yunit)
• Default to :omega vs. :q

4. Implement plot_all_diagnostics(events; savedir="plots/")

• Reproduce all currently hardcoded plots in a consistent format
• Automatically save to pdf and png (maybe specify this in an kwarg)

5. Centralize quantity and unit handling

• Add compute_quantity(events, name) and unit conversion utilities
• Reuse code across all plots

6. Add documentation and test coverage

• Minimal plotting tutorial in README and docs/
• Add plotting smoke tests in test/plots.jl

Benefits

• Eliminates duplication in plotting scripts
• Ensures consistent style and labeling across publications
• Enables interactive exploration of simulation results

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Optional Extensions

• Add support for interactive sliders (via MakieLayout or GLMakie)
• Enable filtering by process types or phase-space cuts
• Support export of data points as CSV or HDF5 for external plotting