shared/iface

The public consumer-facing interfaces. Cross-module imports go only through this package — never into another module's services/ or repository/ directories.

Interface	Provided by	Consumed by
UserProvider	user	every other module
NotificationSender	notification	auth, billing, subscriptions, agents
PDFProvider	documents	billing
GraphProvider	graph	rag
AIModelProvider	aimodels	rag, agents, sales
RAGQueryProvider	rag	agents
JWTProvider	auth	identity, any custom auth integration

This indirection is what keeps consumers decoupled from producers: any implementation — in-process, or a remote HTTP-backed client a fork wires in — satisfies the same interface, so consumer code never changes.