Zero-touch product provisioning: when a request arrives with an unknown
productId and a valid JWT, auto-create a minimal ProductDoc instead of
rejecting. Enables new products to use platform-service immediately.
- auto-register.ts: auto-create ProductDoc with sensible defaults
- Rate limited: max 10 auto-registrations per minute
- Requires valid JWT (unauthenticated requests still rejected)
- Audit logged as product.auto_registered
- request-context.ts: exported extractProductIdAsync with auto-register
- 8 tests: register, duplicate, format validation, rate limit
- New lib/request-context.ts with product validation against cache
- Priority: JWT payload > X-Product-Id header > env var fallback
- Rejects unknown or disabled products with 400 Bad Request
- Augments FastifyRequest with jwtPayload type declaration
- getRequestProductConfig() for modules needing product-specific values
