FEAT(ci): migrate to gitea actions

- Migrate workflows to Gitea Actions
- Configure container registry push

.gitea/workflows/build.yml

@@ -8,8 +8,8 @@ on:
   workflow_dispatch:
 
 env:
-  REGISTRY: ghcr.io
-  IMAGE_NAME: ${{ github.repository }}
+  REGISTRY: gitea0213.kro.kr
+  IMAGE_NAME: ${{ gitea.repository }}
 
 jobs:
   build-and-push:
@@ -29,17 +29,17 @@ jobs:
       - name: Set up Docker Buildx
         uses: docker/setup-buildx-action@v3
 
-      - name: Log in to GitHub Container Registry
+      - name: Log in to Gitea Container Registry
         uses: docker/login-action@v3
         with:
           registry: ${{ env.REGISTRY }}
-          username: ${{ github.actor }}
-          password: ${{ secrets.GITHUB_TOKEN }}
+          username: ${{ gitea.actor }}
+          password: ${{ secrets.GITEA_TOKEN }}
 
       - name: Lowercase repository name
         id: lowercase
         run: |
-          echo "repo=$(echo ${{ github.repository }} | tr '[:upper:]' '[:lower:]')" >> $GITHUB_OUTPUT
+          echo "repo=$(echo ${{ gitea.repository }} | tr '[:upper:]' '[:lower:]')" >> $GITHUB_OUTPUT
 
       - name: Extract metadata (tags, labels)
         id: meta
@@ -77,10 +77,10 @@ jobs:
           echo "---"
 
           # Get commit SHA (full 40 characters)
-          COMMIT_SHA="${{ github.sha }}"
+          COMMIT_SHA="${{ gitea.sha }}"
 
           # Get current branch name
-          BRANCH_NAME="${{ github.ref_name }}"
+          BRANCH_NAME="${{ gitea.ref_name }}"
           echo "Branch: $BRANCH_NAME"
 
           # Method 1: Extract the full SHA tag from docker/metadata-action output
@@ -111,10 +111,10 @@ jobs:
 
       - name: Update kustomization with new image tag
         env:
-          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          GITEA_TOKEN: ${{ secrets.GITEA_TOKEN }}
         run: |
-          git config --global user.name "github-actions[bot]"
-          git config --global user.email "github-actions[bot]@users.noreply.github.com"
+          git config --global user.name "gitea-actions[bot]"
+          git config --global user.email "gitea-actions[bot]@users.noreply.gitea.com"
 
           # Validate that SHA_TAG is not empty
           SHA_TAG="${{ steps.extract-tag.outputs.sha-tag }}"
@@ -124,7 +124,7 @@ jobs:
           fi
 
           # Determine overlay based on branch
-          BRANCH_NAME="${{ github.ref_name }}"
+          BRANCH_NAME="${{ gitea.ref_name }}"
           if [ "$BRANCH_NAME" = "main" ]; then
             OVERLAY="prod"
           elif [ "$BRANCH_NAME" = "develop" ]; then