Preserve all NVAIE repository aliases in mirror mode

[thbertoldi]

Summary

• preserve every catalog-derived NVIDIA ClusterRepo alias when switching to the aggregate private mirror
• expose stable repository_name values for NGC catalog entries and retain those identities in static and dynamic UI flows
• load a shared NVIDIA mirror index only once while keeping source-specific install aliases
• update the Settings CRD and air-gap documentation

Why

AIWorkloads persist spec.source.app.chartRepo by name. The expanded NVAIE catalog installs applications from team repositories such as nvidia-runai, nvidia-omniverse, and nim-nvidia, but mirror mode previously preserved only nvidia and nvidia-blueprints while pruning the team aliases. Switching an existing installation to a mirror could therefore break later upgrades or redeploys.

Validation

• cd operator && go test ./...
• cd ui && npm test (131 tests)
• cd ui && npm run lint
• cd ui && npm run typecheck
• helm lint charts/aif-operator
• helm lint charts/aif-ui
• connected → mirror → connected reconciliation regression coverage