Remove the retired BBCTL package from the umbrella chart

Feature Request

Why

BBCTL has been retired and is no longer maintained as a product, so the umbrella chart should stop rendering it as a core package. Leaving it integrated ships a HelmRelease pointing at a dead package repo and keeps Big Bang carrying support code that exists only for it — the Loki max_line_size: 0 override for the violations dashboard, and the NOTES.txt warning about its Loki/Alloy/Grafana/Monitoring dependencies.

Proposed Solution

Remove BBCTL from the umbrella chart entirely:

• Delete chart/templates/bbctl/, the bbctl values block, and its chart/package-metadata.yaml catalog entry.
• Drop the BBCTL-only Loki max_line_size override and the NOTES.txt dependency warning.
• Remove bbctl from the test values files, the Kyverno namespace exclusion lists, and the values unit test suite.
• Delete docs/packages/core/bbctl.md and regenerate the derived schema, migration metadata, and docs via scripts/generate-package-schemas.sh --write and scripts/generate-values-reference.sh --write.

Breaking change: bbctl.* is removed from values.yaml and values.schema.json. Because the schema sets additionalProperties: false, any existing override file that still sets bbctl: will fail schema validation and must have that block deleted before upgrading.