fix: restore correct namecheap plugin name and add plugin verification

- Change CERTBOT_PLUGIN back to 'dns-namecheap' (correct value)
- Add plugin verification after installation to ensure certbot recognizes it
- This helps troubleshoot plugin recognition issues in Docker environment

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <[email protected]>

Author: Leechael

custom-domain/dstack-ingress/scripts/certman.py

@@ -45,6 +45,15 @@ def install_plugin(self) -> bool:
                 print(f"Failed to install plugin: {result.stderr}", file=sys.stderr)
                 return False
             print(f"Successfully installed {self.provider.CERTBOT_PACKAGE}")
+            
+            # Verify plugin is recognized by certbot
+            verify_cmd = ["certbot", "plugins"]
+            verify_result = subprocess.run(verify_cmd, capture_output=True, text=True)
+            if self.provider.CERTBOT_PLUGIN not in verify_result.stdout:
+                print(f"Warning: Plugin {self.provider.CERTBOT_PLUGIN} not recognized by certbot after installation", file=sys.stderr)
+                print(f"Available plugins: {verify_result.stdout}", file=sys.stderr)
+                return False
+            
             return True
         except Exception as e:
             print(f"Error installing plugin: {e}", file=sys.stderr)

custom-domain/dstack-ingress/scripts/dns_providers/namecheap.py

@@ -11,7 +11,7 @@ class NamecheapDNSProvider(DNSProvider):
     """Namecheap DNS provider implementation."""
 
     DETECT_ENV = "NAMECHEAP_API_KEY"
-    CERTBOT_PLUGIN = "namecheap"
+    CERTBOT_PLUGIN = "dns-namecheap"
     CERTBOT_PACKAGE = "certbot-dns-namecheap"
     CERTBOT_PROPAGATION_SECONDS = 120
     CERTBOT_CREDENTIALS_FILE = "~/.namecheap/namecheap.ini"