Implement the exported functions

[larnsce]

Goal

The exported function set. Imports: tibble and utils. jsonlite, desc, cffr, gh and writexl live in Suggests or Config/Needs/harvest because only data-raw/ and the tests use them. No tidyverse package in Imports.

Rewritten 2026-09-04 per dev/decisions-2026-09.md. Start from R/owd_accessors.R, R/owd_search.R, R/owd_install.R, R/catalog.R and R/zzz.R on the closed PR #15 branch, minus the refresh and cache code.

Functions

• owd_packages(published = NULL): the packages tibble; TRUE keeps published packages, FALSE the rest, NULL all
• owd_datasets(pkg = NULL): datasets tibble, optionally filtered by package
• owd_variables(pkg = NULL, dataset = NULL): variables tibble
• owd_search(query, fields = c("title", "description", "variable_name", "dataset_name")): case-insensitive regex over a prebuilt flat index; returns pkg_name, match_type (package, dataset, variable), dataset_name, field, text
• owd_install(pkg = NULL, ...): install.packages(pkg, repos = c("https://openwashdata.r-universe.dev", "https://cloud.r-project.org"), ...); pkg = NULL installs all published packages after an interactive confirmation showing the count and errors in non-interactive sessions

The catalog is the internal owd_catalog object from R/sysdata.rda, read through one internal accessor so the tables can only come from one place.

Attach behaviour

library(owdata) attaches nothing else. .onAttach() prints one packageStartupMessage(): "owdata catalog: 30 published packages, 48 datasets, 2676 variables (harvested 2026-09-08). Try owd_search(), owd_packages(), owd_install()." The harvest date is the staleness signal; there is no refresh function and no cache.

Acceptance criteria

• Roxygen with examples for every export; the column reference for each table lives in the roxygen of its accessor
• devtools::check() clean
• A behavioural test per export; every expect_error() names its message
• owd_search("groundwater") and owd_search("sanitation") return sensible hits