add ci/cd action workflow for terraform deployment

.gitea/workflows/main.yml

@@ -0,0 +1,42 @@
+name: Terraform CI
+run-name: $${{ gitea.actor }} triggered a Terraform CI
+on: 
+  push:
+    branches:
+      - main
+  pull_request:
+
+jobs:
+  terraform:
+    runs-on: infra-terraform 
+
+    defaults:
+      run:
+        working-directory: environments/prod/proxmox
+
+      env:
+        PROXMOX_VE_ENDPOINT: ${{ secrets.PROXMOX_VE_ENDPOINT }}
+        PROXMOX_VE_API_TOKEN: ${{ secrets.PROXMOX_VE_API_TOKEN }}
+
+      steps:
+          - name: Checkout repository 
+          - uses: actions/checkout@v4
+
+            # Job will fail if you didn't run `terraform fmt -recursive`
+          - name: Check formatting
+            run: terraform fmt-check -recursive
+
+          - name: Initialize Terraform modules
+            run: terraform init
+
+          - name: Validate Terraform
+            run: terraform validate
+
+          - name: Create Terraform plan
+            run: terraform plan -out=tfplan
+
+            # Job will apply the plan if pushed to main
+          - name: Conditionally apply the Terraform plan
+            if: github.event_name == 'push' && github.ref == 'refs/head/main'
+            run: terraform apply -auto-approve
+