Tests should use test database instead of dev database

[kbighorse]

Problem

Tests were connecting to the dev database (ocotilloapi_dev) instead of the test database (ocotilloapi_test).

Root Cause

In db/engine.py, load_dotenv(override=True) overwrites the POSTGRES_DB=ocotilloapi_test environment variable set by the test framework in tests/__init__.py with the value from .env (typically ocotilloapi_dev).

Impact

• Tests may pollute or read from dev database
• Test isolation is compromised
• Unexpected test failures due to database state mismatches

Fix

Change load_dotenv(override=True) to load_dotenv(override=False) so pre-set environment variables (from the test framework) are preserved.

Affected Files

• db/engine.py
• tests/__init__.py (sets test database)