feat: Sprint 1 — staffing assign, dashboard cache, bulk ops, notifications

Staffing "Assign" Button:
- Inline assignment form on each suggestion card in StaffingPanel
- Pre-fills project, dates, hours from search criteria
- 1-click confirm creates allocation with PROPOSED status
- Success/error toasts, removes assigned suggestions from list

Dashboard Redis Caching:
- New cache utility (packages/api/src/lib/cache.ts) with get/set/invalidate
- All 5 dashboard queries wrapped with 60s TTL cache-aside pattern
- Auto-invalidation on allocation + project mutations (fire-and-forget)
- Graceful fallthrough to DB if Redis unavailable

Bulk Operations:
- CSV export for selected resources and projects (apps/web/src/lib/csv-export.ts)
- Project batch delete mutation with cascade (assignments, demands, rules)
- Export/Delete buttons added to BatchActionBar on both list pages

Budget Overrun Notifications:
- checkBudgetThresholds() alerts at 80% (HIGH) and 100% (URGENT)
- Called after every allocation mutation, duplicate-safe
- Targets ADMIN + MANAGER users with SSE delivery

Estimate Approval Reminders:
- checkPendingEstimateReminders() finds SUBMITTED versions > 3 days old
- Cron endpoint: GET /api/cron/estimate-reminders (optional CRON_SECRET auth)
- Creates in-app REMINDER notifications, duplicate-safe

Co-Authored-By: claude-flow <ruv@ruv.net>

packages/api/src/index.ts

@@ -2,3 +2,5 @@ export { appRouter, type AppRouter } from "./router/index.js";
 export { createTRPCContext, createTRPCRouter, createCallerFactory, publicProcedure, protectedProcedure, managerProcedure, controllerProcedure, adminProcedure, requirePermission, loadRoleDefaults, invalidateRoleDefaultsCache } from "./trpc.js";
 export { eventBus, emitAllocationCreated, emitAllocationUpdated, emitAllocationDeleted, emitProjectShifted, emitBudgetWarning, flushPendingEvents, cancelPendingEvents } from "./sse/event-bus.js";
 export { anonymizeResource, anonymizeResources, anonymizeUser, getAnonymizationConfig, getAnonymizationDirectory } from "./lib/anonymization.js";
+export { checkBudgetThresholds } from "./lib/budget-alerts.js";
+export { checkPendingEstimateReminders } from "./lib/estimate-reminders.js";