Model registry

<!-- This is an auto-generated comment: release notes by coderabbit.ai --> ## Summary by CodeRabbit * **New Features** * Name-based model registry with human-readable names, active-model listing, disable/enable, name↔id lookup, and on-chain random selection; owner management CLI; automatic update support; per-model input classes and external-artifact fetching. * **Refactor** * Unified identifier terminology (URI → name) across app and contracts; improved path handling; verification-strategy enum renamed. * **Chores** * Added owner config, new dependency, updated deployments and spell-check vocabulary. * **Tests** * New model-registry, artifact-download, and lifecycle tests with enhanced fixtures. * **Breaking change** * Two operator-selection view functions removed from task manager ABI. <!-- end of auto-generated comment: release notes by coderabbit.ai -->