feat(09-06): NEW /admin/workflow/executions page + pipeline-executions API (ROUTE-07)
- GET /api/admin/pipeline-executions: requireAdmin(), accepts fallbacks_only/pipeline_id/limit params
- Four complete parameterized SQL strings — no alias-in-WHERE bug (HIGH 4 fix)
- JSONB predicate: output_data ? 'user_route_fallback' inlined in EXISTS subquery in WHERE
- has_fallback boolean on every row (true constant in fallbacks-only branches, EXISTS in unfiltered)
- pipeline_id validated against /^\d+$/ before binding; limit capped at 500
- app/admin/workflow/executions/page.tsx: Switch 'Show only fallbacks', pipeline Select filter, per-row fallback badge, links to pipeline detail page
- Locked URL /admin/workflow/executions honored — fresh page over pipeline-engine tables only
lorentz
23a8c7c5d9