koma 0.3.1

Added \value documentation tags to print.koma_forecast and print.koma_seq to comply with CRAN policy.

koma 0.3.0

Fixed frequency-dependent forecasting, estimation, evaluation, weighting, and plotting paths so single-frequency monthly and yearly data work correctly.
Fixed forecast plotting labels for non-quarterly data.
Fixed estimate_sem() for multisession futures.
Improved input validation for forecasting and system_of_equations().
Improved koma_ts metadata handling for attribute preservation across transformations.

Fix pkgdown site build by adding package URL and completing _pkgdown.yml reference index.

Added fan chart support in forecast plots, including density-based visuals built from stochastic draws.
Added growth-rate whiskers to forecast plots when fan charts are enabled.
Improved conditional forecasting behavior and messaging.
Tightened forecast/estimation validation and fixed several forecasting edge cases.
Expanded estimation utilities: support ts inputs, per-series ts→ets overrides, and richer texreg extracts/summaries.
Added/updated documentation and vignettes (error correction, extract methods, and forecast output guidance).
Reduced/adjusted dependencies (e.g., removed expm, tidyr, stringr; moved plotly to Suggests; added standalone Wishart helpers).
Improved CI and tooling (GitHub Actions checks, codecov, release/tag workflows, and renv handling).
Added summary() output for koma_forecast with mean/median and quantile columns.
Added MCMC trace plots via trace_plot() for coefficient diagnostics.
Added running-mean diagnostics via running_mean() and running_mean_plot().
Added autocorrelation diagnostics via acf_plot().