fix: update provider_meta to use user_agent instead of module_name

[pranaydeokar-cd]

📌 Description

• Updated provider_meta configuration to replace module_name with user_agent
• Standardized and upgraded GitHub Actions workflows to use v2 shared workflows
• Added new CI workflows for PR validation, Terraform linting, and security scanning
• Removed deprecated workflows (tflint.yml, tfsec.yml, automerge, old changelog)

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🔄 Type of Change

• 🐛 Bug fix (non-breaking change)
• ✨ New resource / feature
• ♻️ Refactoring
• ⚡ Performance improvement
• 🔒 Security improvement
• 📝 Documentation update
• ⚠️ BREAKING CHANGE
• ⚙️ CI/CD update

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🌍 Terraform Scope

• New resource added
• Existing resource updated
• Variable(s) modified
• Output(s) modified
• Provider / backend configuration change
• CI/CD (Terraform workflow) update
• Examples / usage updated

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✅ Checklist

• Code follows Terraform best practices
• terraform fmt -recursive and terraform validate have been executed
• terraform plan has been reviewed and changes are expected
• Changes are backward compatible (or breaking changes are clearly documented)
• Documentation has been updated (README, examples, etc.)
• Variables and outputs are properly defined and documented
• No sensitive data (secrets, credentials, keys) is exposed

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🧩 Terraform Version & Providers

• Terraform Version:
• Provider(s):

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🧪 Testing

• Tested locally using terraform plan / apply
• Tested in a staging / sandbox environment (if applicable)

Test Details:

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📸 Screenshots / Documentation

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🔗 Related Issues

Closes #

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📝 Additional Notes