fix(orchestrator): make legacy mempool id start/stop/restart the split stack

Found by the .228 lifecycle gate (2026-07-08, first quadlet-mode run):
stop→start on the legacy `mempool` umbrella app id destroyed the mempool
deployment. Under quadlet, package.stop removes the containers; package.start
then failed with `unknown app_id: mempool` because load_manifests drops the
umbrella manifest whenever the three split-stack members are loaded — leaving
nothing to recreate from and the stack down.

Two fixes:
- prod_orchestrator start/stop/restart now resolve the historical
  `mempool`/`mempool-web` id to the split members (archy-mempool-db,
  mempool-api, archy-mempool-web) whenever the umbrella manifest was dropped —
  the same alias install already implements ("installing mempool assembles the
  split stack"). Restart falls back to start for members whose container/unit
  is gone. Legacy umbrella-only nodes are unaffected (alias inactive while the
  umbrella manifest is live).
- is_missing_container_error (3 sites) now recognizes podman 5.x's
  `no such object` inspect phrasing, so a genuinely absent container is
  classified as missing instead of surfacing as a hard inspect error.

Tests: 2 new alias tests + 2 classifier tests; prod_orchestrator suite 61/61
green.

Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>

core/container/src/runtime.rs

@@ -572,6 +572,8 @@ fn is_missing_container_error(stderr: &str) -> bool {
     let stderr = stderr.to_ascii_lowercase();
     stderr.contains("no container with name or id")
         || stderr.contains("no such container")
+        // podman 5.x `inspect` phrasing: `Error: no such object: "name"`
+        || stderr.contains("no such object")
         || stderr.contains("does not exist")
         || stderr.contains("not found")
 }
@@ -1035,6 +1037,16 @@ mod tests {
     use super::*;
     use std::collections::HashMap;
 
+    #[test]
+    fn missing_container_classifier_covers_podman5_phrasings() {
+        // podman 5.x `inspect` phrasing for a missing container.
+        assert!(is_missing_container_error(
+            "Error: no such object: \"mempool\""
+        ));
+        assert!(is_missing_container_error("Error: no such container x"));
+        assert!(!is_missing_container_error("Error: OCI runtime error"));
+    }
+
     fn cfg(context: &str, tag: &str, dockerfile: &str, args: &[(&str, &str)]) -> BuildConfig {
         BuildConfig {
             context: context.to_string(),