Layer 8: Data + Governance

[d3v07]

Blocked until d3v07 reviews and approves or requests changes on frex22's Layers 1-4 PR.

Assignee:
d3v07

Branch:
feature/d3v07-layers-5-8-safety-execution-governance

Context:
Use the Layer 8 architecture image as the visual and technical spec. This layer makes the product auditable: MongoDB target clusters, Evidence Ledger / Audit Store, secrets, run history, verification trace, and policies.

Goal:
Strengthen data and governance surfaces without changing EvidencePack v1 unless explicitly approved.

Required work:

• Ensure ledger / trace writes are complete for diagnosis, approval, application, and verification.
• Add run history records if already compatible with the existing data model.
• Add rollback plan visibility when derivable or already present.
• Add policy check records if possible without schema/API expansion.
• Keep secrets in Secret Manager or local env only.
• Keep dashboard reading EvidencePack v1 JSON only.

Governance value to preserve:

• auditability
• reproducibility
• traceability
• policy enforcement

Operator-inspectable surfaces:

• run history
• evidence packs
• approvals
• verification traces
• policy decisions, if present

Non-negotiable constraints:

• Do not expose credentials to frontend.
• Do not change EvidencePack v1 unless explicitly approved.
• Do not add API routes unless explicitly approved.
• Do not silently mock live policy/run-history behavior.
• Do not pretend planned governance data is live.
• Do not create mutation paths outside the deterministic execution rail.

Acceptance criteria:

• Ledger and trace writes are complete for the golden path.
• Verification trace is inspectable and audit-friendly.
• Run history is shown or documented honestly based on current compatibility.
• Rollback plan is visible if compatible; otherwise represented as planned/not recorded.
• Policy records are shown only if present or honestly marked as not recorded.
• No secrets appear in code, dashboard, screenshots, or logs.

Tests:
Run:
uv run pytest tests/unit/test_ledger_store.py tests/unit/test_orchestrator.py -q
uv run pytest -q

If dashboard governance/history UI is touched:
cd dashboard && npm run lint
cd dashboard && ./node_modules/.bin/tsc --noEmit
cd dashboard && npm run build

Manual QA if UI is touched:

• desktop 1440x1100
• mobile 390x1000
• no horizontal overflow
• no clipped hashes
• no unreadable trace rows
• policy empty states are honest
• rollback visibility does not imply automatic rollback unless implemented

Deviation guard:
Stop and ask before changing EvidencePack v1, renaming tools, adding API routes, adding mutation authority, exposing credentials, or silently mocking live governance behavior.