# Sprint 85 Plan: Safety Case Generation and Formal Assurance Artifacts

## Context

High-assurance domains need structured safety cases, not only test outputs.
Sprint 85 generates formal assurance artifacts from migration evidence.

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## Goals

1. Build machine-readable safety-case model linked to evidence
2. Generate assurance claims, assumptions, and argument trees
3. Track residual risk with explicit ownership
4. Support audit-ready safety-case exports

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## Steps

### Step 1079: Safety case schema (`claim`, `evidence`, `assumption`, `risk`) (12 tests)
### Step 1080: Evidence-to-claim mapping engine (10 tests)
### Step 1081: Assurance argument tree builder (10 tests)
### Step 1082: Residual risk ownership model (10 tests)
### Step 1083: Safety case completeness checker (10 tests)
### Step 1084: Assurance export formats (8 tests)
### Step 1085: `whetstone_generate_safety_case` MCP tool (8 tests)
### Step 1086: `whetstone_get_residual_risks` MCP tool (8 tests)
### Step 1087: Assurance review dossier template (8 tests)
### Step 1088: Sprint 85 integration summary + regression (8 tests)

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## Assurance Rule

- Missing critical claim evidence blocks high-assurance deployment paths.