ggchangepoint 0.3.0

Documentation and coverage

The README now introduces every exported function, grouped by role, and the over-claimed gfpop engine (never wrapped) has been removed from it.
New feature-tour vignette (vignette("ggchangepoint")) walking the full exported surface, including the per-engine wrappers, theme_ggcpt(), and annotate_segments().
The package-level help (?ggchangepoint) was rewritten to describe the unified ggcpt framework and the current 13-method engine list (it previously still claimed “only three changepoint packages”).
New documentation-coverage test asserting every export appears in the README.

New cpt_methods() introspection helper returning a tibble of every known method, its engine, availability status, and whether the engine is installed.
New S3 methods for the ggcpt class: summary(), as_tibble(), as.data.frame(), format(), and plot().
cpt_penalty() gained a documented per-engine penalty-semantics section.

cpt_detect() no longer advertises 13 methods that errored at runtime; match.arg() now enumerates only the wired methods (B7).
cpt_detect() validates method × change_in combinations and errors with a clear message instead of silently mislabelling the result (B3).
signal_blocks() now produces the correct Blocks signal; the segment levels previously collapsed to a single step because the assignment loop ran in reverse (B1).
cpt_metrics() uses one-to-one matching, so recall and f1 can no longer exceed 1 (B2), and no longer warns on empty pred/truth (B6).
ecp_wrapper() returns a correct per-coordinate cp_value for matrix and data.frame input instead of a column-major flattened scalar (B4); cpt_detect() no longer flattens multivariate input before passing it to ecp.
stat_changepoint() maps detected indices back to the x aesthetic so rules land at the correct location on non-1:n axes (B5).
glance.ggcpt() now reports a measured runtime and populates total_cost from the underlying fit when available (B8).
augment.ggcpt() renames data columns position-independently, so it no longer breaks when the data carries more than two columns (B11).
cpt_simulate() @return now documents the seg_id column it actually returns (B9), and the dead show_segments parameter was removed from the internal plot helper (B10).

New ggcpt S3 result class with tidy(), glance(), augment(), and autoplot() methods
New cpt_detect() unified dispatcher for changepoint methods
New geoms: geom_changepoint(), geom_cpt_segment(), geom_cpt_ci(), stat_changepoint()
New first-wave wrappers: WBS/WBS2, NOT, MOSUM, FPOP, Isolate-Detect, TGUH
New ggcpt_compare() and ggcpt_compare_table() for method comparison
New evaluation module: cpt_metrics(), cpt_metrics_annotated(), ggcpt_eval()
New simulator: cpt_simulate()/rcpt() and canonical test signals
New cpt_penalty() helper
New theme_ggcpt() and annotate_segments() for plot customisation

ecp_wrapper() no-change bug fixed: spurious boundary changepoints and NA no longer emitted
size → linewidth migration: cptline_linewidth replaces deprecated cptline_size
match.arg() input validation added to all wrappers
Changepoint convention documented and aligned
“sytle” typo fixed → “style” in documentation
roxygen modernised to "_PACKAGE" sentinel
change_in = "np" alias added (keeps "cpt_np" for backward compatibility)
Full-height changepoint rule default; show_points auto-off above 500 obs
Optional index parameter for time-series axes

Initial release to CRAN.
Exported functions: cpt_wrapper(), ecp_wrapper(), ggcptplot(), ggecpplot().