Parent issue #21

Objective

To setup initial project structure and Database layer

Tasks

• Initialize Go module with Echo framework
• Set up folder structure (cmd/, internal/, pkg/)
• Configure environment loading (koanf)
• Add structured logging (zerolog)
• Set up PostgreSQL (local Docker)
• Configure pgx connection pool
• Write migrations with tern:
  • projects table
  • api_keys table
  • log_batches table (metadata index)
  • alert_rules + alert_events tables