Repo Hygiene: Stop Tracking .env Files

[VivekChaurasiya95]

Sensitive .env files are currently committed in the repository, which is a security risk.

⚠️ Evidence
backend/.env
admin-dashboard/.env
❗ Issue
.env files contain sensitive data and should not be version-controlled.
They are currently tracked instead of using a safe template.
What actually happened?

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📦 Affected Module

(e.g., CIVISIM, AI Civic Drafting, Learning Planner Pro, etc.)

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💻 Environment

• OS:
• Browser:
• Version/Branch:

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Additional Context
Add screenshots, logs, or additional details if applicable.