fix(database): Add missing `dbname` parameter to PostgreSQL DSN connection string

[sm-28601]

Current Behavior

Currently, in database/database.go, the PostgreSQL DSN is constructed without including the dbname parameter, which may lead to connection issues or default database usage.

Expected Behavior

The PostgreSQL DSN should explicitly include the dbname parameter to ensure the application connects to the intended database correctly.

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[sm-28601]

Hi team, I found this while preparing for my GSoC proposal regarding the PostgreSQL database migration. I would love to submit a PR to fix this .