What

Adds buildOracleContext(result: LocalScaffoldResult): OracleContext helper and OracleContext type to @stackbilt/scaffold-core.

Why

After migrating stackbilt-web routes from the local shim to @stackbilt/scaffold-core@1.1.0, the oracle LLM polish pass was receiving {} context — prompt_context is now null because the npm package doesn't emit it. Pro users on the --oracle path were silently getting degraded output.

buildOracleContext derives the same structured context from the existing LocalScaffoldResult fields, without any additional inference or network calls.

Changes

• types.ts: Add OracleContext interface
• index.ts: Add buildOracleContext() function + export OracleContext type
• __tests__/oracle-context.test.ts: 4 tests (field mapping, bindings, topThreats cap, adr002 null)

Consumer update (stackbilt-web)

After this ships, update pages/api/flows/index.ts:

// Before
const oracleResult = await runOracle((result.prompt_context ?? {}) as any, cfEnv as any);

// After
import { buildOracleContext } from '@stackbilt/scaffold-core';
const oracleResult = await runOracle(buildOracleContext(scaffold), cfEnv as any);

Closes charter#224. Part of charter#223 checklist.