Simplify routing to award assignment, seed all CSV entries, fix category mapping

- Remove RoutingRule model and routing engine (replaced by direct award assignment)
- Simplify RoutingMode enum: PARALLEL/POST_MAIN → SHARED, keep EXCLUSIVE
- Remove routing router, routing-rules-editor, and related tests
- Update pipeline, award, and notification code to remove routing references
- Seed: include all CSV entries (no filtering/dedup), AI screening handles duplicates
- Seed: fix non-breaking space (U+00A0) bug in category/issue mapping
- Stage filtering: add duplicate detection that flags projects for admin review

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/server/routers/_app.ts

@@ -37,7 +37,7 @@ import { dashboardRouter } from './dashboard'
 // Round redesign Phase 2 routers
 import { pipelineRouter } from './pipeline'
 import { stageRouter } from './stage'
-import { routingRouter } from './routing'
+
 import { stageFilteringRouter } from './stageFiltering'
 import { stageAssignmentRouter } from './stageAssignment'
 import { cohortRouter } from './cohort'
@@ -87,8 +87,7 @@ export const appRouter = router({
   // Round redesign Phase 2 routers
   pipeline: pipelineRouter,
   stage: stageRouter,
-  routing: routingRouter,
-  stageFiltering: stageFilteringRouter,
+stageFiltering: stageFilteringRouter,
   stageAssignment: stageAssignmentRouter,
   cohort: cohortRouter,
   live: liveRouter,