Atoms

Introduces the grammar atom class to atoms-spec, enabling schema-atoms to publish machine-readable structural contracts for each catalog's atom types. Grammar atoms are referenced by catalog validators for cross-catalog field validation and tooling.

Adds mandatory full delivery cycle: worktree+branch → commit → push → PR → CI green → merge. Skipping any step is a defect. Covers no-PR abandonment, CI bypass, out-of-band production changes, and bulk-operation cycle discipline.

Clarifies that the approval keyword for destructive actions is 'approve' (not 'yes') to prevent ambiguous approvals that could trigger irreversible operations.