Add Makefile targets for all 8 recipes

[kiyeonjeon21]

Priority: P1

Makefile is missing targets for batch-processing, realtime-cdc, data-governance, and ai-ml-platform even though recipe .env files exist.

What to do

• Add 4 missing Makefile targets matching recipe .env files
• Add validate target that runs docker compose config for all recipes
• Add seed target that runs dbt seed && dbt run
• Update make help descriptions

Acceptance criteria

• All 8 recipe .env files have corresponding Makefile targets
• make help lists all new targets
• make validate checks all compose configurations