Fix database schema migration conflicts and optimize Docker startup

[guptapratykshh]

Description
The PR fixes important database schema initialization problems that kept Augur from starting in Docker environments. The augur container was stuck in endless restart loops due to migrations that could not run multiple times and issues with timing during database setup.

these changes fixed the docker in all aspects -

• [schema] Made database migrations able to run multiple times by adding DROP IF EXISTS logic before creating constraints and indexes in 1_augur_new_changes.py.
• [schema] Corrected the PostgreSQL schema search path to include augur_operations and used fully qualified sequence names (augur_operations.users_user_id_seq, augur_data.repo_repo_id_seq).
• [docker] Added a health check to the augur-db service in docker-compose.yml to make sure PostgreSQL is fully set up before starting dependent services.
• [docker] Set HOME=/tmp environment variable to fix Git permission issues during repository cloning.

This PR fixes the issues and the docker log - https://docs.google.com/document/d/11xPTG3JIM6a-dYF1iLFz1sUCE-o7DrxWFuPcF2qZnz0/edit?usp=sharing

Notes for Reviewers

Signed commits

• Yes, I signed my commits.

[guptapratykshh]

closing this one , as mentioned that new initialization process upcoming, it makes sense to avoid tech debt there. @MoralCode

[MoralCode]

sounds good! the new process is probably going to take a while to arrive as id like to pilot it in the unit tests first.

that said, I think the docker initialization issues will largely be fixed by #3559