- Add CachedProfileStore wrapper with configurable TTL and automatic cleanup
- Add cacheEntry struct with profile data and expiration timestamp
- Add Get method with cache-first lookup and automatic cache population on miss
- Add cache invalidation on Create, UpdateState, and Delete operations
- Add background cleanup goroutine with ticker running at TTL/2 interval
- Add manual Invalidate and InvalidateAll methods for cache
- Add Ping method to PostgresProfileStore to check database connection status
- Add Ping method to ProfileRepository interface
- Add /api/v1/health/live endpoint for liveness checks (always returns alive if service is running)
- Add /api/v1/health/ready endpoint for readiness checks with database connectivity validation
- Add readinessHandler that returns SERVICE_UNAVAILABLE status when database ping fails
- Add DatabaseConfig struct with DSN field for Postgres connection string
- Add package documentation comments for ES2Config/DatabaseConfig/LoadES2Config
- Normalize ES2Config field alignment for BaseURL/APIKey/InsecureSkipVerify/FunctionalityRequesterID
- Remove InMemoryProfileStore struct and all methods (Create/Get/List/UpdateState/Delete) from profile.go
- Remove sync package import
- Add profileRow struct with ICCID/EID/IMSI/MCC/MNC/ProfileType/State/TenantID/ActivationCode/CreatedAt/UpdatedAt fields mapped to esim_profiles table with indexes on EID/IMSI/State/TenantID
- Add NewPostgresProfileStore with DSN validation, GORM connection setup with Warn logging, and AutoMigrate for esim_profiles schema
- Add Create/Get/List/UpdateState/Delete methods implementing ProfileRepository interface with
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