Align Work Graph reports with OrgX schema

[hopeatina]

Summary

• maps hook-derived top-level events to the Work Graph report schema enum while preserving runtime hook detail in metadata
• adds required investigation fingerprint/generated_at fields and object-shaped why_not_100 entries
• keeps the attribution spine runtime_hook source events intact for richer review context

Verification

• HOME=$(mktemp -d) env -u ORGX_API_KEY npm run build:core
• HOME=$(mktemp -d) env -u ORGX_API_KEY node ./scripts/run-targeted-test.mjs tests/hooks/post-reporting-event.test.mjs tests/hooks/work-graph-reconcile.test.mjs
• npm pack --dry-run --json and package entry inspection
• generated a Codex reconciler report and parsed it with Code/orgx clientWorkGraphReportSchema
• pnpm vitest run tests/api.client.work-graph.reports.route.spec.ts --reporter=dot in Code/orgx/orgx