Fix ggplot2 imports and polish utility functions for publication

Blocking issue #1: Replace all ggplot2::function() calls with bare
references in R/colors.R, R/logo.R, R/theme.R. The package already has
import(ggplot2) in NAMESPACE which makes these available directly; the ::
prefixes were triggering R CMD check 'undefined global function' NOTEs for
~30+ unimported symbols (element_line, element_rect, theme_grey, margin,
rel, unit, discrete_scale, etc.).

Suggestion #6: Replace class(x) == "character" with "character" %in% class(x)
in R/db.R (countCleanr and simpleCap). The == pattern breaks on S3 objects
with multiple class attributes.

Suggestion #7: Vectorise simpleCap() to handle multi-element input correctly.
Previously strsplit(x, ' ')[[1]] only processed the first element; now uses
unname(vapply()) to capitalise each vector element independently while
preserving the original scalar behaviour (no names attribute on output).

Suggestion #9: Convert match_test() from raw cat() calls to structured
writeLines() output with proper formatting and spacing between sections.

NEWS.md

@@ -0,0 +1,16 @@
+# civilytics 0.3.2
+
+## New features
+- Added comprehensive test coverage for the `prop_conf` module, including
+  correctness checks against `binom.test()` for Clopper-Pearson intervals and
+  formula-based verification for Wald and Agresti-Coull intervals.
+
+## Bug fixes
+- Removed vendored headshot images (`Knowles_Headshot_2019_good.jpg`,
+  `Knowles_Headshot_2019_prisma.jpg`) from `inst/img/` to prevent personal
+  photos from being distributed with the package. The `plot_jpeg()` example
+  now references a generic placeholder path instead of a specific headshot.
+
+## Internal
+- Renamed `LICENSE.md` to `LICENSE` for R packaging convention compliance so
+  that the LGPL-3 license ships correctly with built tarballs.