feat: standardize environment variable naming and UTC datetime format

- Rename ENVIRONMENT to ENVIRONMENT_TYPE for clarity and consistency
- Update all datetime generation to use UTC timezone (TZ=UTC date)
- Add environment variable and datetime conventions to copilot-instructions.md
- Update base.env.tpl template with new ENVIRONMENT_TYPE naming
- Update configure-env.sh script to generate UTC timestamps
- Regenerated staging and production environment files to verify changes

Following project conventions for:
- Environment variable naming: ENVIRONMENT_TYPE instead of ENVIRONMENT
- DateTime format: Always use UTC timezone for all timestamps and dates

Author: josecelano

.github/copilot-instructions.md

@@ -491,6 +491,15 @@ The project includes a comprehensive linting script that validates all file type
 - **Variables**: Use `terraform.tfvars` for sensitive/local config (git-ignored)
 - **Templates**: Use `.tpl` extension for templated files
 
+#### Environment Variables and Configuration
+
+- **Environment Variable Naming**: Use `ENVIRONMENT_TYPE` instead of `ENVIRONMENT` for clarity and consistency
+- **DateTime Format**: Always use UTC timezone for all timestamps and dates
+  - **Format Example**: `TZ=UTC date` for script generation timestamps
+  - **Generated Files**: Headers should show UTC timestamps (e.g., "Generated on: mar 05 ago 2025 12:32:00 UTC")
+- **Configuration Templates**: Environment-specific configuration should use template substitution with `.tpl` extensions
+- **Variable Documentation**: Mark mandatory variables with 🔴 indicators in configuration files
+
 ### Testing Requirements
 
 #### Infrastructure Tests

docs/guides/providers/hetzner/hetzner-cloud-setup-guide.md

@@ -125,13 +125,13 @@ DNS_TOKEN="$HETZNER_DNS_API_TOKEN"
 echo "DNS token length: ${#DNS_TOKEN} characters"
 # Should show: DNS token length: 32 characters
 
-# Test Cloud API access
-curl -H "Authorization: Bearer $CLOUD_TOKEN" \
+# Test Cloud API access (silent mode for clean JSON output)
+curl -s -H "Authorization: Bearer $CLOUD_TOKEN" \
      "https://api.hetzner.cloud/v1/servers" | jq
 # Expected output: {"servers": []}
 
-# Test DNS API access
-curl -H "Auth-API-Token: $DNS_TOKEN" \
+# Test DNS API access (silent mode for clean JSON output)
+curl -s -H "Auth-API-Token: $DNS_TOKEN" \
      "https://dns.hetzner.com/api/v1/zones" | jq
 # Expected output: {"zones": [...]}
 ```
@@ -221,8 +221,8 @@ GRAFANA_DOMAIN=grafana.torrust-demo.dev
 CERTBOT_EMAIL=admin@torrust-demo.dev
 
 # Floating IP Configuration (your actual IPs)
-FLOATING_IP_V4=78.47.140.132
-FLOATING_IP_V6=2a01:4f8:1c17:a01d::/64
+FLOATING_IPV4=78.47.140.132
+FLOATING_IPV6=2a01:4f8:1c17:a01d::/64
 
 # Generate secure passwords
 MYSQL_ROOT_PASSWORD=$(openssl rand -base64 32)
@@ -257,8 +257,8 @@ GRAFANA_DOMAIN=grafana.torrust-demo.com
 CERTBOT_EMAIL=admin@torrust-demo.com
 
 # Floating IP Configuration (your actual IPs)
-FLOATING_IP_V4=78.47.140.132
-FLOATING_IP_V6=2a01:4f8:1c17:a01d::/64
+FLOATING_IPV4=78.47.140.132
+FLOATING_IPV6=2a01:4f8:1c17:a01d::/64
 
 # Generate secure passwords
 MYSQL_ROOT_PASSWORD=$(openssl rand -base64 32)
@@ -307,13 +307,136 @@ make app-deploy ENVIRONMENT_TYPE=production ENVIRONMENT_FILE=production-hetzner
 ## Step 7: Configure DNS
 
 After deployment, you need to configure DNS to point your domain to the floating
-IP. See the [Deployment Guide - Part 3: DNS Configuration](../../deployment-guide.md#-part-3-dns-configuration)
-for detailed instructions on:
+IP. This section provides complete working examples for Hetzner DNS API configuration.
 
-- Creating DNS zones via Hetzner DNS API
-- Setting up A/AAAA records for your subdomains
-- Configuring automatic DNS management
-- Testing DNS propagation
+### 7.1 Create DNS Zone
+
+First, create a DNS zone for your domain:
+
+```bash
+# Source your environment configuration with DNS API token
+source infrastructure/config/providers/hetzner.env
+
+# Create DNS zone for your domain
+curl -s -H "Auth-API-Token: $HETZNER_DNS_API_TOKEN" \
+  -H "Content-Type: application/json" \
+  -X POST \
+  -d '{"name": "torrust-demo.dev", "ttl": 86400}' \
+  https://dns.hetzner.com/api/v1/zones | jq
+```
+
+**Expected Response:**
+
+```json
+{
+  "zone": {
+    "id": "Vpew4Pb3YoDjBVHMvV9AHB",
+    "name": "torrust-demo.dev",
+    "ttl": 86400,
+    "registrar": "",
+    "legacy_dns_host": "",
+    "legacy_ns": [],
+    "ns": [
+      "hydrogen.ns.hetzner.com",
+      "oxygen.ns.hetzner.com",
+      "helium.ns.hetzner.de"
+    ],
+    "created": "2025-01-13T19:17:12Z",
+    "verified": "0001-01-01T00:00:00Z",
+    "modified": "2025-01-13T19:17:12Z",
+    "project": "",
+    "owner": "",
+    "permission": "",
+    "zone_type": "PRIMARY",
+    "status": "verified",
+    "paused": false,
+    "is_secondary_dns": false,
+    "txt_verification": {
+      "name": "",
+      "token": ""
+    },
+    "records_count": 2
+  }
+}
+```
+
+### 7.2 Create DNS A Records
+
+Create A records for your tracker and monitoring subdomains:
+
+```bash
+# Create tracker subdomain A record
+curl -s -H "Auth-API-Token: $HETZNER_DNS_API_TOKEN" \
+  -H "Content-Type: application/json" \
+  -X POST \
+  -d '{
+    "value": "78.47.140.132",
+    "ttl": 86400,
+    "type": "A",
+    "name": "tracker",
+    "zone_id": "Vpew4Pb3YoDjBVHMvV9AHB"
+  }' \
+  https://dns.hetzner.com/api/v1/records | jq
+
+# Create grafana subdomain A record
+curl -s -H "Auth-API-Token: $HETZNER_DNS_API_TOKEN" \
+  -H "Content-Type: application/json" \
+  -X POST \
+  -d '{
+    "value": "78.47.140.132",
+    "ttl": 86400,
+    "type": "A",
+    "name": "grafana",
+    "zone_id": "Vpew4Pb3YoDjBVHMvV9AHB"
+  }' \
+  https://dns.hetzner.com/api/v1/records | jq
+```
+
+**Expected Response for each record:**
+
+```json
+{
+  "record": {
+    "id": "0de308260c254fa933b2c89312d6eb08",
+    "type": "A",
+    "name": "tracker",
+    "value": "78.47.140.132",
+    "zone_id": "Vpew4Pb3YoDjBVHMvV9AHB",
+    "ttl": 86400,
+    "created": "2025-01-13T19:48:51Z",
+    "modified": "2025-01-13T19:48:51Z"
+  }
+}
+```
+
+### 7.3 Verify DNS Configuration
+
+Verify your DNS records are created correctly:
+
+```bash
+# List all records in your zone
+curl -s -H "Auth-API-Token: $HETZNER_DNS_API_TOKEN" \
+  "https://dns.hetzner.com/api/v1/records?zone_id=Vpew4Pb3YoDjBVHMvV9AHB" | jq
+
+# Test DNS resolution
+dig tracker.torrust-demo.dev
+dig grafana.torrust-demo.dev
+```
+
+### 7.4 Configure Nameservers at Domain Registrar
+
+Finally, configure your domain registrar to use Hetzner's nameservers:
+
+```text
+hydrogen.ns.hetzner.com
+oxygen.ns.hetzner.com
+helium.ns.hetzner.de
+```
+
+**Important**: Replace `torrust-demo.dev` with your actual domain, `78.47.140.132`
+with your floating IP, and `Vpew4Pb3YoDjBVHMvV9AHB` with your actual zone ID.
+
+For additional DNS configuration options, see the [Deployment Guide - Part 3: DNS Configuration](../../deployment-guide.md#-part-3-dns-configuration).
 
 ## Step 5.5: Optional - Configure Persistent Volume for Data Persistence