Design a multi-tenant SaaS platform's container architecture, addressing tenant isolation and noisy-neighbor risk.

Cover: the isolation-model spectrum from shared containers with logical (application-level) tenant separation, to per-tenant namespaces/resource quotas in Kubernetes, to fully dedicated container/cluster-per-tenant for the highest-isolation tier customers — and the cost/complexity trade-off across that spectrum; resource limits/quotas to prevent one tenant's load spike from degrading others (the noisy-neighbor problem) regardless of which isolation model is chosen; and how this isolation choice typically maps to pricing tiers (e.g., dedicated infrastructure reserved for enterprise/premium tena