feat: injectable StringFormatter + Slugify (app-admin & api-core) + api-core DateFormatter

[adrians5j]

Injectable, decoratable formatting features on both admin and backend. Combines #5517 (admin) and #5526 (api-core), rebased from release/6.5.0 onto next.

Features

@webiny/app-admin

• StringFormatter — consumer-facing string-transform API (parallel to the existing DateFormatter). Exposes slugify() today; methods grow over time.
• Slugify — single-method (execute()) feature holding Webiny's canonical slug options; the fine-grained decorate seam behind StringFormatter.slugify().

@webiny/api-core

• StringFormatter / Slugify — backend counterparts using api-core's @webiny/feature/api DI. No hooks (no React).
• DateFormatter — deterministic absolute date/time formatting (UTC, YYYY-MM-DD HH:mm), decoratable. No viewer-locale dependence, unlike the admin side.

Consumers use StringFormatter; to change slug logic a project decorates Slugify alone — a smaller surface than decorating the whole formatter. The canonical slug options are a private detail of the default impl, so the contract stays independent of any specific slug library.

Override (per project) — decorate the fine-grained seam

const MySlugify = Slugify.createDecorator(() => {
    return {
        execute: value => {
            return value.trim().toLowerCase().replace(/\s+/g, "_");
        }
    };
});

container.registerDecorator(MySlugify);

Migrated

• app-admin: RolesPresenter, ApiKeysPresenter, TeamsPresenter
• app-aco: FolderTreePresenter, folder create dialog (useCreateDialog)
• app-headless-cms: ModelGroupPresenter
• api-headless-cms: CreateGroupRepository now injects StringFormatter instead of importing the toSlug util.
• Dropped the now-unused slugify dependency from app-aco and app-headless-cms.

Left as-is on purpose

• app-website-builder experiment toKey — strict machine-key transform ({ lower: true, strict: true }), not a display slug; kept as direct slugify for now (follow-up).
• PagePath / pagePathFromTitle — pure value objects / exported utils with no DI seam.
• @webiny/form useGenerateSlug — base-layer package that cannot depend on @webiny/app-admin.
• contentModelGroup zod validation schema — pure schema factory with no DI seam; keeps using the toSlug util directly.

Docs

• ai-context/core-features-reference.md — added StringFormatter / Slugify / DateFormatter.

TODO / follow-ups

• Bring the app-website-builder experiment toKey into the feature system as its own StringFormatter method backed by its own fine-grained feature.

Notes

• Supersedes feat: add injectable StringFormatter + Slugify features (app-admin) #5517 and feat(api-core): add injectable DateFormatter + StringFormatter/Slugify #5526 (both targeted release/6.5.0; closed in favor of this).

🤖 Generated with Claude Code

[adrians5j]

/vitest

[github-actions]

Vitest tests have been initiated (for more information, click here). ✨

Group	Status
No storage	❌ 0/57 passed
DDB	❌ 0/3 passed
DDB+OS	❌ 0/19 passed
SQL	❌ 0/10 passed
PGlite	❌ 0/10 passed

❌ Failed packages

DDB

• api-aco
• api-websockets
• api-headless-cms (5/6)
• api-headless-cms-aco

[adrians5j]

/e2e

[github-actions]

Cypress E2E tests have been initiated (for more information, click here). ✨

Database	Status	Admin URL
DDB	🔄 Deploying...	-
DDB+OS	🔄 Deploying...	-