Land foundations: assessment, ADR-001/002/003, FLEX-WP-0005, Go skeleton

Pre-implementation assessment and boundary review
(docs/pre-implementation-assessment.md) lead to three ADRs:
- ADR-001 Go + repo skeleton
- ADR-002 Rego-in-Markdown policy package format
- ADR-003 Topaz-aligned MVP (Topaz spike moves into foundations)

New workplan FLEX-WP-0005 (Foundations and Topaz Alignment) is inserted
between WP-0001 (done) and WP-0002 (core). WP-0002 pins Rego-in-Markdown
for P2.3; WP-0004 P4.1 refocused from Topaz evaluation to Topaz adapter.

Go skeleton at repo root: cmd/flex-auth + internal/{registry,policy,
decision,audit,adapters} + pkg/api + Makefile + .golangci.yml + GitHub
Actions CI. make ci green locally; bin/flex-auth --version works.

INTENT/SCOPE cite the NetKingdom IAM Profile and add the ops-warden /
ops-bridge disjoint-surface clarifications.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

internal/decision/doc.go

@@ -0,0 +1,10 @@
+// Package decision implements check, batch_check, list_allowed, and
+// explain on top of the registry and policy packages.
+//
+// Decision envelopes carry effect, reason, matched policy version,
+// matched rule, resource metadata, subject metadata, obligations,
+// diagnostics, and provenance. Envelopes are identical for local and
+// delegated evaluation per ADR-003.
+//
+// Implementation lands in FLEX-WP-0002 P2.4 and P2.5.
+package decision