update: add all files

Author: Augment Agent

.github/workflows/README.md

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+# GitHub Actions Workflows
+
+## Active Workflows
+
+### `deploy-mig-staging.yml` - Production Deployment Pipeline
+
+**Purpose**: Deploy application to GCP Managed Instance Group (MIG) with Terraform
+
+**Trigger**: Manual (`workflow_dispatch`)
+
+**Required Input**:
+- `tag`: Docker image tag to deploy (e.g., `v1.0.2`)
+
+**What it does**:
+1. Builds Docker image from specified tag
+2. Pushes to Google Artifact Registry
+3. Updates Terraform configuration with new image tag
+4. Applies Terraform changes to update instance template
+5. Performs rolling restart of MIG instances
+6. Runs comprehensive health checks
+7. Verifies HTTPS endpoints and CORS headers
+
+**Environment**: `staging`
+
+**Required Secrets**:
+- `WIF_PROVIDER`: Workload Identity Federation provider
+- `WIF_SERVICE_ACCOUNT`: Service account email
+
+**Duration**: ~10-15 minutes
+
+**Usage**:
+```bash
+# Go to Actions tab in GitHub
+# Select "Deploy to GCP MIG Staging"
+# Click "Run workflow"
+# Enter tag: v1.0.2
+# Click "Run workflow"
+```
+
+---
+
+### Other Workflows
+
+- **`go-test.yml`**: Runs Go tests on pull requests
+- **`golangci-lint.yml`**: Runs linting checks
+- **`conventional-commits.yml`**: Validates commit messages
+- **`release.yml`**: Creates GitHub releases
+- **`clear_cache.yaml`**: Clears GitHub Actions cache
+
+## Deployment Flow
+
+```
+Tag Release (v1.0.2)
+    ↓
+Trigger Workflow (Manual)
+    ↓
+Build & Push Image
+    ↓
+Update Terraform Config
+    ↓
+Apply Infrastructure Changes
+    ↓
+Rolling Restart MIG
+    ↓
+Health Checks & Verification
+    ↓
+Deployment Summary
+```
+
+## Infrastructure Details
+
+- **Project**: `merkle-oracle-staging`
+- **MIG**: `merkle-oracle-node-mig-staging`
+- **Domain**: `https://merkle-staging4.zengate-dev.com`
+- **Registry**: `europe-west1-docker.pkg.dev/merkle-oracle-staging/merkle-oracle-node`
+
+## Endpoints Verified
+
+After deployment, these endpoints are automatically tested:
+
+- ✅ `/healthcheck` - Application health
+- ✅ `/objects` - API functionality
+- ✅ `/docs` - API documentation
+- ✅ `/docs/swagger.json` - OpenAPI spec
+- ✅ CORS headers - Cross-origin support
+
+## Rollback
+
+To rollback to a previous version:
+1. Trigger workflow with previous tag
+2. Wait for deployment to complete
+3. Verify endpoints
+
+## Monitoring
+
+View deployment status:
+- GitHub Actions: Real-time logs
+- GCP Console: Instance health and metrics
+- Application logs: Via SSH to instances
+
+## Notes
+
+- Old `deploy-gcp.yml` workflow has been removed (single-instance deployment)
+- New workflow uses MIG for production-ready deployments
+- Terraform manages all infrastructure
+- Zero-downtime deployments via rolling updates
+- Automatic health checks and rollback on failure