🔒 GDPR registry leaf — modules/users/lib/dataProvider.registry.js (Map-keyed)

[PierreBrisorgueil]

Config-free, import-safe leaf registry that optional modules use to self-register a GDPR data provider — mirrors modules/organizations/lib/orgRemoval.registry.js, but Map-keyed by a stable string key (not a Set of fn identities → an inline-arrow registration in a *.init.js can't double-register).

Scope — modules/users/lib/dataProvider.registry.js

• registerDataProvider({ key, axis: 'user'|'org', retention: 'delete'|'anonymize', export?, erase? }) — TypeError on bad key / non-fn export/erase.
• runDataExport(payload) → { data: { [key]: … }, modules: [...] } (the modules manifest makes export completeness auditable).
• runDataErasure(payload) → per-provider result manifest; sequential for…of await, errors propagate (fail-closed).
• _reset() test helper.
• Imports no service (avoids the import cycle that forced the previous removal).

DoD

• Unit suite: single-provider run, registration order, error-propagate-and-abort, zero-provider no-throw, non-fn rejection, _reset clears, key-dedup (re-register same key overwrites, not duplicates).
• /verify green; coverage ≥ threshold.

Depends on: none (foundation).

Created via /dev:issue