What

Create docs/compliance/ISO_OVERVIEW.md — an ecosystem-level summary that consolidates ISO standard mappings across all kcenon systems into a single navigable index.

• Current: Per-system compliance docs exist (or are planned) but no cross-system index
• Expected: A single document listing every ISO standard the ecosystem touches, which systems implement which controls, and links to per-system mapping docs
• Scope: docs only

Why

• This is the third acceptance criterion of #645 (Ecosystem-wide ISO compliance EPIC)
• Procurement/audit reviewers need one entry point — without an overview, they have to crawl each repo to assemble the picture
• Keeps the EPIC's compliance posture self-documenting

Where

• New file: docs/compliance/ISO_OVERVIEW.md
• Modify: README.md (top-level link to the overview)

How

Technical Approach

Use the table from EPIC #645 as the structural skeleton:

For each row include: scope summary, evidence pointer (workflow / code / doc), and any operator responsibilities.

Acceptance Criteria

• docs/compliance/ISO_OVERVIEW.md exists with the standards × systems matrix
• README links to the overview from a top-level "Compliance" section
• Each cell with "Documented" links to the corresponding per-system mapping doc
• Operator responsibilities (e.g., key rotation, retention policy) called out

Part of #645.

Dependencies

This issue can land independently, but the per-system "Documented" cells will be empty until logger and pacs companion sub-issues land. Add the matrix rows now and fill in links as those merge.