# spicy 0.11.0

## New features

### `table_continuous_lm()`

* Cluster-robust SEs via `cluster` and four `vcov` choices
  (`"CR0"`–`"CR3"`), dispatched to `clubSandwich` with
  Satterthwaite df (`clubSandwich` in `Suggests`).
* `vcov = "bootstrap"` (nonparametric or cluster) and
  `vcov = "jackknife"` (leave-one-out / leave-one-cluster-out)
  variance estimators in pure base R, controlled by `boot_n`.
* Three new `effect_size` choices alongside `"f2"`: Cohen's
  `"d"`, Hedges' `"g"` (two-group only), Hays' `"omega2"`. New
  `effect_size_ci` adds noncentral *t* / *F* CIs rendered inline
  as `0.18 [0.07, 0.30]`.
* `HC*` estimators delegate to `sandwich::vcovHC()`;
  rank-deficient fits return a clean rank-by-rank covariance.

### Harmonisation across the table family

* Shared reporting vocabulary (`decimal_mark`, `p_digits`,
  `align`, named-`labels`) now spans `cross_tab()`, `freq()` and
  the three `table_*()` helpers, including APA-style p-value
  notation (`<.001` / `.045`, no leading zero).
* `table_categorical()`'s `assoc_measure` accepts a per-variable
  spec. When measures differ across rows the column collapses to
  `"Effect size"` and an APA-style `Note.` line documents the
  per-variable measure; `phi` on a non-2x2 errors.
* All three `table_*()` functions gain `as.data.frame()`,
  `tibble::as_tibble()`, `broom::tidy()` and `broom::glance()`
  methods (`broom` in `Suggests`).

## Quality and robustness

* **Classed conditions.** Errors and warnings now carry stable
  classes (`spicy_error` / `spicy_warning` plus 11 leaf classes
  documented in `?spicy`), so downstream code can dispatch via
  `tryCatch()` / `withCallingHandlers()` instead of matching
  message strings. `rlang (>= 1.1.0)` required.
* **Structured cli messages.** Multi-line errors and warnings
  (vcov fallbacks, bootstrap/jackknife failures, `padding`
  migration, `labels` length mismatch) render as cli bullets.
* **Locale-deterministic ordering.** Sorts in `varlist()`,
  `freq()`, `cross_tab()` and `table_*()` use
  `method = "radix"`. Output is byte-stable across locales and
  platforms, matching Stata / SPSS guarantees.
* **Edge-case hardening.** `varlist()` / `code_book()` /
  `cross_tab()` / `freq()` no longer crash on zero-length or
  all-NA `Date` / `POSIXct` / `character` columns or factors
  with no observed levels (R 4.6.0 `sort()` segfaults on these
  inputs).
* **Snapshot-locked rendering.** `tests/testthat/test-snapshots.R`
  pins the exact console output of every spicy print method, so
  any unintended formatting drift surfaces as a PR diff.
* **API stability contract.** `?spicy` documents which exports
  are stable, stabilising or internal. pkgdown reference groups
  exports via four `@family` tags.
* **Cross-software validation.** All 13 association measures
  agree with PSPP 2.0 (`CROSSTABS /STATISTICS=ALL`, 65 / 65
  statistics on four datasets); Cohen's *d* and Hedges' *g*
  noncentral CIs are tested numerically against
  `effectsize::cohens_d()` / `effectsize::hedges_g()`
  (`tolerance = 1e-6`); point-estimate formulas and asymptotic
  standard errors follow `DescTools` (Signorell et al.).

## Improvements

* `cross_tab()` warns when `correct = TRUE` is ignored on a
  non-2x2 sub-table, when `weights` contains `NA`, and notes
  statistics computed on a sub-table after empty rows / columns
  are pruned.
* `cross_tab()` validates `decimal_mark`, `p_digits` and
  `simulate_B` up front; `freq()` validates `decimal_mark` and
  tightens `digits` to a non-negative integer.
* A user category literally named `"N"` or `"Total"` is no longer
  mis-rendered as the totals row in `cross_tab()`.
* `table_continuous_lm(output = "long")` returns `n`, `df1`, `df2`
  as integer columns; `predictor_label` preserved on the
  degenerate-model fallback path.
* `cramer_v()` / `phi()` doc states the CI uses the Fisher
  z-transformation (point estimate and p-value identical to
  `DescTools` / SPSS).
* `uncertainty_coef()` doc states entropy uses `0 log 0 = 0`
  (matching SPSS, PSPP, Stata, Cover & Thomas).

## Bug fixes

* `label_from_names()` raises actionable errors on duplicate or
  empty new column names; trims whitespace and preserves the
  input class.
* `table_continuous_lm(output = "data.frame")` names contrast CI
  columns from `ci_level` (was hardcoded to 95 %).
* The categorical-predictor global Wald *F* degrades to `NA` on
  a singular coefficient covariance submatrix.
* The degenerate-table branch of `cramer_v()`, `yule_q()`,
  `gamma_gk()`, `kendall_tau_b()` and `somers_d()` respects
  `detail`: scalar `NA_real_` by default, fully shaped
  `spicy_assoc_detail` when `detail = TRUE`.
* `uncertainty_coef()` returns a finite estimate (was `NaN`) when
  a marginal is zero.
* `somers_d(direction = "symmetric")` returns the harmonic mean
  of the two asymmetric values, matching SPSS / PSPP `CROSSTABS`.
* `print.spicy_assoc_detail()` / `print.spicy_assoc_table()` use
  APA-strict `<.001` / `.045` notation, matching the rest of the
  package.
* `varlist()` / `code_book()` honour `factor_levels = "all"` for
  `haven_labelled` columns: declared-but-unobserved labels appear
  in the `Values` summary.
* `copy_clipboard()` rejects `row.names.as.col` vectors of length
  ≠ 1 and empty strings; accumulates all messages from
  `clipr::write_clip()` instead of overwriting.
* `mean_n()` / `sum_n()` reject non-integer `min_valid >= 1` and
  `min_valid > ncol`; their `digits` requires a non-negative
  integer.

## Breaking changes

* `table_continuous_lm()` and `table_categorical()` default to
  decimal-point alignment for numeric columns
  (`align = "decimal"`). Pass `align = "auto"` for the previous
  behaviour.
* `build_ascii_table()` / `spicy_print_table()`: `padding`
  switches from a string enum to a non-negative integer.
  Default `2L` (was `+5L`); printed tables are roughly 40 %
  narrower. **Migration**: `"compact" -> 0L`, `"normal" -> 2L`,
  `"wide" -> 4L`.
* `table_categorical(assoc_measure = "auto")` on a 2x2 table
  picks `phi` instead of `cramer_v`. Numeric value unchanged
  (|phi| = V on 2x2); only the column label changes.
* `freq()` drops observations with `NA` weights (with a warning)
  instead of recoding them to zero. Aligns with `cross_tab()`.
* `table_continuous_lm(output = "long")` returns `NA` in
  `es_type` / `es_value` when `effect_size = "none"` (was
  `"f2"`), and renames `sum_w` to `weighted_n`.

# spicy 0.10.0

## New features

* `code_book()` now accepts tidyselect-style variable selectors through `...`, matching `varlist()` and `vl()`.

* `code_book()` gains a `filename` argument for the base name of CSV, Excel, and PDF exports. When `NULL` (the default), the filename is derived from `title` and falls back to `"Codebook"` when needed. Filenames are sanitized to portable ASCII consistently across platforms.

* `varlist()` now summarizes matrix and array columns by their dimensions, and counts valid, missing, and distinct observations by rows.

* `freq()` gains a `factor_levels` argument that mirrors `varlist()` and `code_book()`. With `factor_levels = "all"`, declared-but-unobserved factor and labelled levels appear in the output with `n = 0`, matching SPSS `FREQUENCIES`; the default `"observed"` preserves the previous Stata `tab`-style behavior.

## Improvements

* `varlist()` now displays missing values as `<NA>` and `<NaN>` in the `Values` summary when `include_na = TRUE`, and quotes literal `"NA"`, `"NaN"`, and empty-string values so they cannot be confused with the missing markers.

* `varlist()` now emits a column-named warning and marks the failing cell as `<error: ...>` when a column cannot be summarized, instead of silently writing `"Invalid or unsupported format"`. Remaining columns are unaffected.

* `varlist()` produces more precise Viewer titles for extraction, pipe, and literal `get("name")` expressions, while keeping ambiguous dynamic calls anonymous (`vl: <data>`).

* `code_book()` now rejects partial-match names in `...` (e.g. `val = TRUE`, `tit = "x"`) that would otherwise be silently treated as tidyselect expressions, and surfaces `varlist()` selection errors directly.

* `freq()` now resolves the `weights` argument via tidy-eval, so column references nested in compound expressions (e.g. `weights = if (use_w) col else NULL`) work as expected. Qualified expressions like `weights = df2$w` continue to take precedence over column lookup.

* `freq()` validates `digits`, `sort`, `weights`, and the logical scalar arguments (`valid`, `cum`, `rescale`, `styled`) more strictly at the public boundary, with clearer error messages for non-finite values, `NA`, multi-element inputs, and non-numeric weight vectors.

* `freq()` now documents the interaction of `weights` containing `NA` with `rescale = TRUE` (Stata `pweight` semantics) and the dropping of unused factor / labelled levels (Stata `tab` semantics, with `code_book(factor_levels = "all")` as the schema-style alternative).

## Bug fixes

* `varlist()` now displays labelled values in the same prefixed-label order for compact and `values = TRUE` summaries; previously the compact summary used data order.

* `varlist(values = TRUE)` now deduplicates element types when summarizing list-columns. Previously `list(1L, 2L, "a")` produced `"List(3): character, integer, integer"`; now produces `"List(3): character, integer"`.

* `include_na = TRUE` now correctly appends `<NA>` markers for list-columns in both `varlist()` modes; previously it had no effect on this column type.

* `varlist()` now validates column names up front and gives clearer errors for missing, empty, `NA`, or duplicate names.

* `varlist()` now errors clearly when tidyselect expressions try to rename columns; `...` is for selecting variables, not renaming.

* `freq(data, x, weights = NULL)` now correctly treats the explicit `NULL` as "no weighting" instead of emitting a misleading `"variable 'NULL' not found"` error. Parameterized patterns like `weights = if (use_w) wts else NULL` are now supported.

* `print()` for `spicy_freq_table` no longer crashes when the `var_label` attribute is `NA_character_`, numeric, or multi-element; the `Label:` line is silently skipped for any value that is not a single non-empty string.

* `freq()` no longer surfaces the name of the ignored `data` vector in the printed footer when both `data` and `x` are passed as vectors. The footer now consistently shows the analyzed vector's name.

# spicy 0.9.0

## Breaking changes

* `table_continuous()` now enables inferential output by default when `by` is
  supplied. With a grouping variable, the `p` column from `test` is shown
  automatically (previous default hid it). This aligns the two table helpers:
  `table_continuous()` stays descriptive when `by` is absent, and reports the
  test *p*-value when `by` is supplied, matching `table_continuous_lm()`'s
  inferential default. To preserve the previous behavior, pass
  `p_value = FALSE` explicitly. `statistic` and `effect_size` remain `FALSE`
  by default and must still be enabled consciously.

* `varlist()` now displays observed factor levels by default in `Values`,
  matching its role as a quick inspection of the current data. Use
  `factor_levels = "all"` to display unused factor levels as well, which was
  the previous default behavior and remains the default in `code_book()`.

## Minor improvements

* `code_book()` gains a `factor_levels` argument. It defaults to `"all"` so
  exported codebooks continue to document all declared factor levels,
  including unused levels; use `"observed"` to mirror `varlist()` output.

* `freq()` now prints the `Freq.` column as integers regardless of
  `digits`, which continues to control percentage precision. This matches
  the convention of SPSS, Stata, and SAS `PROC FREQ` for weighted counts
  and keeps the two numeric concepts (discrete counts vs. continuous
  percentages) visually distinct.

* `freq(..., styled = FALSE)` now returns a genuinely plain `data.frame`
  with no `spicy_freq_table` rendering metadata clinging to it, so
  `str()`, `dput()`, and downstream programmatic use see only the
  tabulation columns. The metadata attributes (`digits`, `data_name`,
  `var_name`, `var_label`, `class_name`, `n_total`, `n_valid`,
  `weighted`, `rescaled`, `weight_var`) are now documented in
  `@return` and remain available on the invisibly returned
  `spicy_freq_table` object when `styled = TRUE` (the default).

* `table_continuous_lm()` documentation now clarifies why `p_value = TRUE`
  and `r2 = "r2"` are the defaults, and robust-variance fallback warnings
  are now more explicit when a model matrix is singular.

## Bug fixes

* `freq()` now correctly resolves qualified weight expressions such as
  `weights = other$w` or `weights = other[["w"]]` even when the referenced
  column name also exists in `data`. Previously the bare-name fallback
  could silently pull the weight vector from the wrong data frame when
  column names collided.

* `freq()` with `sort` and missing values now keeps the `NA` row at the
  end of the tabulation so the printed `Cum. Percent` and
  `Cum. Valid Percent` columns stay monotonic and match the
  Valid → Missing → Total display layout. Sorting previously could push
  the `NA` row between valid rows and make cumulative percentages appear
  to jump.

* `varlist()` now preserves literal `"NA"` and empty-string values in the
  `Values` summary instead of removing them as if they were missing values.

* `varlist()` now distinguishes actual `NA` values from `NaN` in the
  `Values` summary when `include_na = TRUE`.

* `varlist(values = TRUE)` now preserves factor level order in the
  `Values` summary, matching the default compact factor display.

* `varlist()` now validates `values`, `tbl`, and `include_na` up front and
  gives a clear error when one of them is not `TRUE` or `FALSE`.

# spicy 0.8.0

## New features

* `table_continuous_lm()` adds APA-style bivariate linear-model tables for continuous outcomes. It acts as the model-based companion to `table_continuous()` for reporting fitted mean comparisons or slopes in an `lm` framework, with one predictor per model, model-based means for categorical predictors, optional case weights, classical or HC0-HC5 variance estimators, multiple output formats (ASCII, tinytable, gt, flextable, Excel, clipboard, and Word), `output = "data.frame"` for the wide raw table, `output = "long"` for the analytic long table, and configurable display of tests, confidence intervals, fit statistics, and effect sizes.

## Minor improvements

* Installed package vignettes now avoid embedding heavy HTML table and codebook widgets during CRAN builds, reducing package size while preserving rich pkgdown article rendering.

* Website and vignette coverage now includes `table_continuous_lm()`, using the bundled `sochealth` data throughout and adding a dedicated article for model-based continuous summary tables.

* `table_continuous()` and `table_continuous_lm()` now support dedicated display precision for effect-size columns, and `table_continuous_lm()` also supports separate precision for `R²` columns, so model fit and effect sizes can be formatted independently from descriptive values and test statistics.

* `table_continuous_lm()` now keeps `n` as the unweighted analytic sample size in wide and rendered outputs, and can optionally add a separate `Weighted n` column reporting the sum of case weights.

# spicy 0.7.0

## New features

* `table_continuous()` is a new helper for continuous summary tables. It computes descriptive statistics (mean, SD, min, max, confidence interval of the mean, and n) for numeric variables, with tidyselect column selection, optional grouping via `by`, and multiple output formats (ASCII, tinytable, gt, flextable, Excel, clipboard, and Word).

* `table_continuous()` gains `effect_size` and `effect_size_ci` arguments. When `by` is used, `effect_size = TRUE` adds an "ES" column with the appropriate measure (Hedges' g, eta-squared, rank-biserial `r_rb`, or epsilon-squared) chosen automatically based on the test method and number of groups, and `effect_size_ci = TRUE` appends the confidence interval in brackets.

* `table_continuous()` gains a `test` argument (`"welch"`, `"student"`, or `"nonparametric"`) to choose the group-comparison method, along with independent `p_value` and `statistic` display toggles so users can request either or both outputs when `by` is used.

* ASCII console tables now split oversized outputs into stacked horizontal panels, repeating the left-most identifier columns so wide `freq()`, `cross_tab()`, `table_categorical()`, and `table_continuous()` prints stay readable in narrow consoles.

## Breaking changes

* `table_categorical()` replaces `table_apa()` as the public helper for categorical summary tables. It uses `select` and `by`, supports grouped cross-tabulation or one-way frequency-style tables when `by = NULL`, and consolidates output formats under a single `output` argument. Migrate existing `table_apa()` calls to `table_categorical()`, use `output = "default"` for ASCII tables and `output = "data.frame"` for plain data frames, and replace former `output = "wide"` / `style = "report"` paths with the formatted output engines.

* Excel export now uses `openxlsx2` instead of `openxlsx` for a lighter dependency footprint (no Rcpp compilation required).

## Minor improvements

* Package citation metadata now uses the current package title and CRAN DOI, so `citation("spicy")` matches `DESCRIPTION` and points to the package DOI.

* `table_categorical()` and `table_continuous()` now print shorter ASCII titles without appending the input data frame name, and no longer require `officer` for `output = "flextable"` alone; `officer` is now required only for Word export paths that actually write `.docx` files.

* `table_continuous()` now accepts tidyselect syntax in `exclude` in addition to character vectors, and no longer warns that `test` is ignored when it is still needed to compute effect sizes.

# spicy 0.6.0

## New features

* New family of association measure functions for contingency tables: `assoc_measures()`, `contingency_coef()`, `gamma_gk()`, `goodman_kruskal_tau()`, `kendall_tau_b()`, `kendall_tau_c()`, `lambda_gk()`, `phi()`, `somers_d()`, `uncertainty_coef()`, and `yule_q()`. Each returns a numeric scalar by default; pass `detail = TRUE` for a named vector with estimate, confidence interval, and p-value.

* `cross_tab()` gains `assoc_measure` and `assoc_ci` arguments. When both variables are ordered factors, it automatically selects Kendall's Tau-b instead of Cramer's V. The note format changes from `Chi-2: 18.0 (df = 4)` to `Chi-2(4) = 18.0`. Numeric attributes (`chi2`, `df`, `p_value`, `assoc_measure`, `assoc_value`, `assoc_result`) are now attached to the output data frame.

* `table_apa()` now dynamically labels the association measure column based on the measure used, instead of always showing "Cramer's V". New `assoc_measure` and `assoc_ci` arguments are passed through to `cross_tab()`.

* `table_apa()` gains `output = "gt"` to produce a `gt_tbl` object with APA-style formatting, column spanners, and alignment.

* `table_apa()` now correctly centers spanner labels over their column pairs in `tinytable` and `flextable` output.

* All association measure functions and `assoc_measures()` gain a `digits` argument (default 3) that controls the number of decimal places when printed. The p-value always uses 3 decimal places or `< 0.001`.

* `detail = TRUE` results now print with formatted output (aligned columns, fixed decimal places) via a new `print.spicy_assoc_detail()` method. `assoc_measures()` output uses a new `print.spicy_assoc_table()` method with the same formatting.

* New bundled dataset `sochealth`: a simulated social-health survey (n = 1200, 24 variables) with variable labels, ordered factors, survey weights, and missing values. Includes four Likert-scaled life satisfaction items (`life_sat_health`, `life_sat_work`, `life_sat_relationships`, `life_sat_standard`) for demonstrating `mean_n()`, `sum_n()`, and `count_n()`.

## Bug fixes

* `count_n()` now correctly counts `NA` values when `count = NA` and `strict = TRUE` are both used. List columns are now reported in verbose mode instead of causing silent errors.

* `cross_tab()` rescale logic now operates on complete cases only, so the weighted total N matches the unweighted N when missing values are present (consistent with Stata behavior).

* `freq()` now uses true `NA` consistently (instead of the `"<NA>"` string) in both weighted and unweighted paths. `cum_valid_prop` is now correctly `NA` for missing rows. Invalid `digits` and `sort` values are rejected with clear error messages.

* `mean_n()` and `sum_n()` now validate `min_valid` and `digits` arguments, rejecting non-numeric, negative, or multi-element values.

* `mean_n()`, `sum_n()`, and `count_n()` no longer trigger a tidyselect deprecation warning when `select` receives a character vector. Character vectors are now automatically wrapped with `all_of()`.

* `table_apa()` now preserves the original factor level order in row variables instead of sorting alphabetically. When `drop_na = FALSE`, the `(Missing)` category is placed at the bottom of each variable's levels. `percent_digits`, `p_digits`, and `v_digits` are now validated.

* `table_apa()` p-values no longer wrap across lines in `tinytable` HTML output.

## Breaking changes

* `cramer_v()` now accepts a `detail` argument. By default it returns a numeric scalar (as before). Pass `detail = TRUE` to get a 4-element named vector (`estimate`, `ci_lower`, `ci_upper`, `p_value`), or `detail = TRUE, conf_level = NULL` for a 2-element vector (`estimate`, `p_value`) without CI.

# spicy 0.5.0

## New features

* New `table_apa()` helper to build APA-ready cross-tab reports with multiple output formats (`wide`, `long`, `tinytable`, `flextable`, `excel`, `clipboard`, `word`).
* `table_apa()` exposes key `cross_tab()` controls for weighting and inference (`weights`, `rescale`, `correct`, `simulate_p`, `simulate_B`) and now handles missing values explicitly when `drop_na = FALSE`.

## Bug fixes

* `count_n()` no longer crashes when `special = "NaN"` is used with non-numeric columns. Passing `count = NA` now errors with a message directing to `special = "NA"`.
* `cross_tab()` fixes a spurious rescale warning for explicit all-ones weights and aligns the Cramer's V formula with `cramer_v()`.
* `table_apa()` no longer leaks global options on error. The `simulate_p` default is aligned to `FALSE`.
* `varlist()` title generation no longer crashes on unrecognizable expressions.

## Minor improvements

* `copy_clipboard()` parameter `message` renamed to `show_message`.
* `freq()` now dispatches printing correctly via S3.
* Removed unused `collapse` and `stringi` from `Imports`.


# spicy 0.4.2

* `cross_tab()` hardening: improved vector-mode detection (including labelled vectors), stricter weight validation, safer rescaling, and clearer early errors (e.g., explicit `y = NULL`).
* `cross_tab()` statistics are now computed on non-empty margins in grouped tables, avoiding spurious `NA` results; internal core path refactored to remove `dplyr`/`tibble` from computation while preserving user-facing behavior.
* `freq()` now errors clearly when `x` is missing for data.frame input and validates rescaling when weight sums are zero/non-finite.
* `count_n()`, `mean_n()`, and `sum_n()` regex mode is hardened (`regex = TRUE` now validates/defaults `select` safely).
* `mean_n()` and `sum_n()` now return `NA` (with warning) when no numeric columns are selected.
* `label_from_names()` now validates input type (`data.frame`/tibble required).
* `cramer_v()` now returns `NA` with warning for degenerate tables.
* Dependency optimization: `DT` and `clipr` moved to `Suggests`; optional runtime checks added in `code_book()` and `copy_clipboard()`.
* Tests expanded with regression coverage for all the above edge cases.


# spicy 0.4.1

* Fixed CRAN incoming check notes by removing non-standard top-level files.

# spicy 0.4.0

* Print methods have been fully redesigned to produce clean, aligned ASCII tables inspired by Stata's layout. The new implementation improves formatting, adds optional color support, and provides more consistent handling of totals and column spacing.

* Output from `freq()` and `cross_tab()` now benefits from the enhanced
  `print.spicy()` formatting, offering clearer, more readable summary tables.

* Documentation and internal tests were updated for clarity and consistency.

* `cross_tab()` gains an explicit `correct` argument to control the use of
  Yates' continuity correction for Chi-squared tests in 2x2 tables. The default
  behavior remains unchanged.

* The documentation of `cross_tab()` was refined and harmonized, with a clearer
  high-level description, improved parameter wording, and expanded examples.

* Minor cosmetic improvements were made to `varlist()` output: the title prefix
  now uses `vl:` instead of `VARLIST`, and the column name `Ndist_val` was renamed
  to `N_distinct` for improved readability and consistency.

* Minor cosmetic improvement: ASCII table output no longer includes a closing
  bottom rule by default.


# spicy 0.3.0

* New function `code_book()`, which generates a comprehensive variable
  codebook that can be viewed interactively and exported to multiple
  formats (copy, print, CSV, Excel, PDF).

# spicy 0.2.1

* `label_from_names()` now correctly handles edge cases when the
  separator appears in the label or is missing.

# spicy 0.2.0

* New function `label_from_names()` to derive and assign variable labels
  from headers of the form `"name<sep>label"` (e.g. `"name. label"`).
  Especially useful for LimeSurvey CSV exports (*Export results* ->
  *CSV* -> *Headings: Question code & question text*), where the default
  separator is `". "`.

# spicy 0.1.0

## Initial release

* Introduces a collection of tools for variable inspection, descriptive
  summaries, and data exploration.
* Provides functions to:
  - Extract variable metadata and display compact summaries (`varlist()`).
  - Compute frequency tables (`freq()`), cross-tabulations (`cross_tab()`),
    and Cramer's V for categorical associations (`cramer_v()`).
  - Generate descriptive statistics such as means (`mean_n()`), sums
    (`sum_n()`), and counts (`count_n()`) with automatic handling of
    missing data.
  - Copy data (`copy_clipboard()`) directly to the clipboard for quick export.
