Add Anthropic API, test environment, remove locale settings

Feature 1: Anthropic API Integration
- Add @anthropic-ai/sdk with adapter wrapping OpenAI-shaped interface
- Support Claude models (opus, sonnet, haiku) with extended thinking
- Auto-reset model on provider switch, JSON retry logic
- Add Claude model pricing to ai-usage tracker
- Update AI settings form with Anthropic provider option

Feature 2: Remove Locale Settings UI
- Strip Localization tab from admin settings
- Remove i18n settings from router inferCategory and getFeatureFlags
- Keep franc document language detection intact

Feature 3: Test Environment with Role Impersonation
- Add isTest field to User, Program, Project, Competition models
- Test environment service: create/teardown with realistic dummy data
- JWT-based impersonation for test users (@test.local emails)
- Impersonation banner with quick-switch between test roles
- Test environment panel in admin settings (SUPER_ADMIN only)
- Email redirect: @test.local emails routed to admin with [TEST] prefix
- Complete data isolation: 45+ isTest:false filters across platform
  - All global queries on User/Project/Program/Competition
  - AI services blocked from processing test data
  - Cron jobs skip test rounds/users
  - Analytics/exports exclude test data
  - Admin layout/pickers hide test programs

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

prisma/migrations/20260221000000_add_test_isolation_anthropic_remove_locale/migration.sql

@@ -0,0 +1,8 @@
+-- Add isTest field to User, Program, Project, Competition for test environment isolation
+ALTER TABLE "User" ADD COLUMN "isTest" BOOLEAN NOT NULL DEFAULT false;
+ALTER TABLE "Program" ADD COLUMN "isTest" BOOLEAN NOT NULL DEFAULT false;
+ALTER TABLE "Project" ADD COLUMN "isTest" BOOLEAN NOT NULL DEFAULT false;
+ALTER TABLE "Competition" ADD COLUMN "isTest" BOOLEAN NOT NULL DEFAULT false;
+
+-- Index for efficient test data filtering
+CREATE INDEX "Competition_isTest_idx" ON "Competition"("isTest");