Enhance Immich deployment process by removing old single-container instances and updating service configurations

- Added logic to remove any existing single-container 'immich' instances to prevent conflicts with the new multi-container 'immich_server' stack.
- Updated `build-auto-installer-iso.sh` to utilize configuration files from the `configs/` directory for Nginx and systemd service, ensuring proper setup.
- Modified deployment scripts to ensure the removal of old containers and improved handling of Immich stack creation.
- Updated documentation to reflect changes in service configurations and critical build checklist items.

core/archipelago/src/api/rpc.rs

@@ -791,6 +791,17 @@ impl RpcHandler {
         if stdout.contains("immich_server") {
             return Err(anyhow::anyhow!("Immich already installed. Stop and remove it first."));
         }
+        // Remove old single-container 'immich' if present (wrong port mapping, blocks immich_server)
+        if stdout.contains("immich\n") || stdout.lines().any(|l| l.trim() == "immich") {
+            let _ = tokio::process::Command::new("sudo")
+                .args(["podman", "stop", "immich"])
+                .output()
+                .await;
+            let _ = tokio::process::Command::new("sudo")
+                .args(["podman", "rm", "-f", "immich"])
+                .output()
+                .await;
+        }
 
         let images = [
             "ghcr.io/immich-app/postgres:14-vectorchord0.4.3-pgvectors0.2.0",