feat: Sprint 3 — automation, intelligence, skill marketplace

Auto-Staffing Suggestions (A6):
- generateAutoSuggestions() ranks top-3 resources on demand creation
- Uses existing staffing engine (skill 40%, availability 30%, cost 20%, util 10%)
- Creates in-app notification with match scores for managers
- Triggered after createDemandRequirement and partial fillDemandRequirement

Vacation Conflict Detection (A7):
- checkVacationConflicts() warns when >50% chapter absent on same days
- Returns warnings array in approve/batchApprove responses (advisory, non-blocking)
- Creates VACATION_CONFLICT_WARNING notification for approver

Weekly Chargeability Alerts (A10):
- checkChargeabilityAlerts() finds resources >15pp below target
- Cron endpoint: GET /api/cron/chargeability-alerts
- Duplicate-safe by resourceId + month composite key

Rate Card Auto-Apply (A11):
- lookupRate() finds best matching rate card line (weighted scoring)
- Auto-fills demand line rates in estimate create/updateDraft when rates are 0
- Marks auto-filled lines with metadata.autoAppliedRateCard
- New lookupDemandLineRate query for on-demand UI lookups

Public Holiday Auto-Import (A12):
- autoImportPublicHolidays() generates holidays by resource federal state
- Cron endpoint: GET /api/cron/public-holidays?year=2027
- Duplicate-safe, uses existing getPublicHolidays() from shared

Skill Marketplace MVP (G6):
- New page: /analytics/skill-marketplace with 3 sections
- Skill Search: filter by name, proficiency, availability, sortable results
- Skill Gap Heat Map: supply vs demand per skill, shortage/surplus indicators
- Skill Distribution: top-20 horizontal bar chart (reuses SkillDistributionChart)
- New getSkillMarketplace query in resource router
- Sidebar nav link under Analytics for ADMIN/MANAGER/CONTROLLER

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

packages/api/src/index.ts

@@ -4,3 +4,7 @@ export { eventBus, emitAllocationCreated, emitAllocationUpdated, emitAllocationD
 export { anonymizeResource, anonymizeResources, anonymizeUser, getAnonymizationConfig, getAnonymizationDirectory } from "./lib/anonymization.js";
 export { checkBudgetThresholds } from "./lib/budget-alerts.js";
 export { checkPendingEstimateReminders } from "./lib/estimate-reminders.js";
+export { checkChargeabilityAlerts } from "./lib/chargeability-alerts.js";
+export { checkVacationConflicts, checkBatchVacationConflicts } from "./lib/vacation-conflicts.js";
+export { lookupRate, type RateCardLookupParams, type RateCardLookupResult } from "./lib/rate-card-lookup.js";
+export { autoImportPublicHolidays, type AutoImportResult } from "./lib/holiday-auto-import.js";