Consolidates the .zddc policy language — scattered today across ZddcFile struct
comments, defaults.zddc.yaml, and ARCHITECTURE.md — into one authoritative spec:
- document model + cascade (levels root→leaf, virtual paths:, fences) and the
rule that decisions resolve at the target's OWN dir (the bug class we hit);
- the decision pipeline: active-admin bypass → WORM mask → cascade ACL, plus
elevation + default-allow-on-empty-tree;
- ACL composition, with the two deliberately-different rules stated plainly
(role membership unions up the tree; permissions take the deepest match);
- a per-key reference table (type + cascade semantics + meaning) for all ~25
keys, including the mergeOverlay trap for adding new keys;
- reserved namespaces (.zddc.d, .zddc.zip);
- a reserved `when:` extension point for sandboxed, side-effect-free
expressions (CEL/expr-lang) — the safe alternative to raw JS, complementing
the existing OPA/Rego Decider seam;
- validation + the two executable backings (Layer 1 engine, Layer 2 matrix).
Policy-as-data: operators express behaviour in .zddc; the app enforces. Per the
chosen direction (formalize first; sandboxed expressions for the conditional gap).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
