chore!: make update public rather than exported

[seabbs-bot]

Summary

First half of #221: update moves from export to public.

Several ecosystem packages (and plenty outside it) have their own update-shaped verb. Exporting a name this generic risks the same ambiguous-binding clash #233 hit with as_turing, where two packages both exporting a same-named generic function makes the bare name unresolvable when both are loaded together. public.jl already carries this pattern for several other names (flat_dimension, reconstruct, params_table, ...); update fits the same shape.

A caller now reaches it as ComposedDistributions.update(...) or using ComposedDistributions: update.

Blast radius

update is this package's single most heavily used verb — about 150 call sites across 18 files (test suite + doc tutorials) relied on the implicit export to call it unqualified inside a @testitem/tutorial script (TestItemRunner auto-usings the tested package per item, which only brings in exported names, not public ones). Fixed all of them: added an explicit using ComposedDistributions: update to each affected testitem/script.

One real build failure caught by running docs, not by inspection: docs/src/getting-started/index.md has a genuinely executable @example overview block using bare update(...) (unlike most of the other affected doc pages, where update only appears in prose/tables/non-executed ```julia blocks) — fixed by adding the import to that block's using line.

The remaining [update](@ref) cross-reference warnings across several doc pages are cosmetic (not build-breaking) and match a pre-existing pattern already tolerated in this repo for other public-not-exported names (flat_dimension, as_logdensity, logdensity, to_constrained, flatten, unflatten are already in the same "no docstring found for Main.X" state on main, confirmed by diffing against a pristine checkout) — not something this PR need chase further.

Test plan

• task test-fast: 1625/1625 pass
• task test-quality: 228/241 pass, 13 broken (pre-existing expected-broken tests, unrelated)
• task docs-fast: builds clean (was failing on the index.md executable block before the fix above)

NEWS.md carries the breaking-change note.

This was opened by a bot. Please ping @seabbs for any questions.

[github-actions]

Try this Pull Request!

Option 1: Julia Package Manager

Open Julia and type:

import Pkg
Pkg.activate(temp=true)
Pkg.add(url="https://github.com/EpiAware/ComposedDistributions.jl", rev="chore/update-export-to-public-221")
using ComposedDistributions

Option 2: Local Checkout

If you have the repo locally:

git checkout chore/update-export-to-public-221
julia --project=. -e "using Pkg; Pkg.instantiate()"