fix(security): remove tracked secrets and add .env.example

[way2nafea]

Summary

This PR improves the security of the project by removing tracked environment secrets and adopting environment variable best practices.

Changes Made

• Removed the tracked backend/.env file from Git.
• Added backend/.env.example with placeholder values for local development.
• Added .gitignore entries to prevent committing environment files.
• Updated docker-compose.yml to use environment variable substitution instead of hardcoded credentials.
• Updated the documentation with instructions for configuring the environment.

Issue

Closes #150

Type of Change

• Bug fix
• Security improvement
• New feature
• Documentation only

Testing

• Verified that .env is no longer tracked.
• Verified that the application uses environment variables from .env.
• Verified that docker-compose.yml starts correctly with environment variables.
• Confirmed that .env.example can be used to create a local .env.

Screenshots

1. .gitignore

Shows the updated .gitignore configuration to ensure .env and other sensitive/generated files are excluded from version control.

2. .env.example

Shows the newly added .env.example file containing placeholder values for local development. No sensitive credentials are included.

3. docker-compose.yml

Shows the updated Docker Compose configuration using the env_file directive and environment variable-based configuration instead of hardcoded credentials.

Notes

This PR does not rewrite Git history or rotate previously committed secrets. Those actions should be performed by the repository maintainers if necessary.

[github-actions]

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[nensii21]

The description is currently incomplete. Please update it with:

A clear summary of the changes made.
The issue number this PR addresses (e.g. Closes #123).
The type of change.
How you tested the implementation.
Add screenshots and videos anout your implementation.

Once the PR description is updated, and the CI workflow is failing. I'll verify whether this is caused by the repository configuration or by the changes in this PR. If it's related to the PR, please update it accordingly.

[way2nafea]

Hi @nensii21,

I've addressed the previous Frontend CI issue by updating the frontend package-lock.json and pushed the changes to this PR.

I also noticed that the workflows are currently awaiting maintainer approval. Whenever you have time, could you please approve the workflows so the CI checks can run?

Thank you!

[nensii21]

one CI check is still failing have a look.once its updated kindly let me know i will review it and merge this PR