[Improvement] Add DB connection retry and better error handling

[zaibamachhaliya]

db.js needs:

• Connection retry logic (max 3 attempts)
• Better error messages
• Pool size from env
• SSL config for production
• Connection timeout from env
• sync({ force: false }) by default
• Proper logging with winston/pino

Files: config/db.js

[zaibamachhaliya]

Hi @BHUVANSH855 Please assign this to me.

[nancy-verma780]

please assign this issue to me under ssoc'26