Replace dead upstream images with custom build services; add retry logic

dtagdevsec/mailoney and dtagdevsec/elasticpot are unavailable on Docker Hub
("manifest unknown"), causing the entire deployment to abort and cascade-
interrupt all other image pulls.

- Convert smtp and elasticsearch to build services with custom Python
  honeypots: smtp emulates Postfix ESMTP (EHLO/AUTH/MAIL/RCPT logging),
  elasticsearch emulates ES 7.17 HTTP API (logs recon probes like /_cat/,
  /_cluster/, /_nodes/, /_security/)
- Both use ARG BASE_IMAGE so they participate in per-decky distro variation
- Add _compose_with_retry() to deployer: 3 attempts with exponential backoff
  (5s → 10s → 20s) for transient network failures; permanent errors
  ("manifest unknown", "pull access denied") are detected and not retried
- Update test_services.py and test_composer.py: smtp/elasticsearch moved
  from UPSTREAM_SERVICES to BUILD_SERVICES (314 tests passing)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

tests/test_composer.py

@@ -20,13 +20,13 @@ APT_COMPATIBLE = {
 }
 
 BUILD_SERVICES = [
-    "http", "rdp", "smb", "ftp", "pop3", "imap",
-    "mysql", "mssql", "redis", "mongodb", "postgres",
+    "http", "rdp", "smb", "ftp", "smtp", "elasticsearch",
+    "pop3", "imap", "mysql", "mssql", "redis", "mongodb", "postgres",
     "ldap", "vnc", "docker_api", "k8s", "sip",
     "mqtt", "llmnr", "snmp", "tftp",
 ]
 
-UPSTREAM_SERVICES = ["ssh", "telnet", "smtp", "elasticsearch", "conpot"]
+UPSTREAM_SERVICES = ["ssh", "telnet", "conpot"]
 
 
 def _make_config(services, distro="debian", base_image=None, build_base=None):