fix: docker crash on startup caused by missing OpenCV system libs

[devanmolx]

Fixes #184

Problem

python:3.11-slim doesn't include libGL which cv2 requires, causing an
immediate crash on startup:

ImportError: libGL.so.1: cannot open shared object file: No such file or directory

Changes

Added to Dockerfile apt-get install:

• libgl1 — provides libGL.so.1 required by cv2
• libglib2.0-0 — glib dependencies also needed by cv2

How to verify

1. docker compose build --no-cache
2. docker compose up -d
3. docker exec -it fireform-app bash
4. python src/main.py — should run past the import stage

Type of change

• Bug fix (non-breaking change which fixes an issue)

Checklist

• Self-reviewed my changes
• No new warnings introduced
• Tested locally and verified fix works