v1.4.523

Changes

PR #2243 by taljeon and ksylvan: fix(ai): refresh model catalogs after vendor membership changes

• Fixed model catalogs so they refresh automatically after vendor membership changes, ensuring newly registered vendors are reflected immediately.
• Simplified cache invalidation in AddVendors by taking the modelsMu lock and clearing the cached models, reducing the change from 463 added lines to 25.
• Reduced GetModels to a concise lock-and-read implementation, removing the retry loop and defensive copies.
• Removed the modelsVersion, modelsLoading, and modelsDiscovery machinery, along with vendorsSnapshot(), eliminating unnecessary generation tracking and waiter coalescing.
• Reconciled model catalog synchronization with main, preserving generation-scoped invalidation behavior while integrating the upstream concurrent-model-read regression fix and its test coverage.