Some work on dev/loghistplot.R

[gklorfine]

This PR merges some work I've done on dev/loghistplot.R:

Commit 743d091 replaced deprecated functions (e.g., ggplot2::opts() -> ggplot2::theme()) and arguments to get the plots in working order.

• Beyond this, only plot.background = element_blank() lines were added to the theme() of plots (to get the plots to properly layer on top of one another)

Commit 29476b6 contains work assisted by Codex (GPT-5.6 Sol). This includes:

• A bins = 30 argument with validation for positive whole numbers
• Computes shared histogram breaks but computes counts separately for each binary outcome
• Adds mirrored count labels as a secondary y-axis
• Forces the probability axis to 0–1.
• Use coord_cartesian() to solve warnings from dropping observations

Commit f867fb was to fix the previous commit (fixed forcing x to start at 0)

All other commits were merges from master -> GK-work3. No files were touched other than dev/loghistplot.R