fix(launcher): reuse MPC container across restarts to preserve logs

The launcher removed and recreated the MPC container on every boot
(docker rm -f + docker compose up -d), dropping Docker's container-ID-keyed
logs each restart. The rm -f worked around a name conflict from running as a
different compose project every boot (random temp compose path, no -p).

Pass an explicit `-p mpc` compose project so Compose reuses the existing
container when the config is unchanged (preserving its logs) and recreates it
only when the rendered config changes (e.g. image digest). No name-conflict
cleanup is needed: a launcher change re-keys the CVM disk (the key is derived
from the launcher's compose measurement), so a new launcher always boots on a
fresh disk with no prior mpc-node container.

Also note in the TDX guide that logs persist across a restart but are cleared
on an upgrade.

Author: barakeinav1

crates/tee-launcher/src/compose.rs

@@ -59,13 +59,11 @@ pub fn launch_mpc_container(
     let compose_file = render_compose_file(platform, port_mappings, image_name, manifest_digest)?;
     let compose_path = compose_file.path().display().to_string();
 
-    // Remove any existing container from a previous run (by name, independent of compose file)
-    let _ = Command::new("docker")
-        .args(["rm", "-f", MPC_CONTAINER_NAME])
-        .output();
-
+    // Use a stable compose project (`-p`) so the container is reused across
+    // restarts rather than recreated, preserving its logs. Compose
+    // recreates it only when the rendered config (e.g. image digest) changes.
     let run_output = Command::new("docker")
-        .args(["compose", "-f", &compose_path, "up", "-d"])
+        .args(["compose", "-p", "mpc", "-f", &compose_path, "up", "-d"])
         .output()
         .map_err(|inner| LauncherError::DockerRunFailed {
             image_hash: manifest_digest.clone(),

docs/running-an-mpc-node-in-tdx-external-guide.md

@@ -966,6 +966,10 @@ Full flag reference and `.env` field-by-field documentation:
 Dstack provides a dedicated web page to view CVM information, including links to the Docker logs.
 More details can be found in [Phala's guide](https://github.com/Dstack-TEE/dstack?tab=readme-ov-file#deploy-an-app).
 
+> **Log retention:** the MPC container is reused across **restarts**, so its
+> logs are preserved and remain viewable here after a restart. An **upgrade**
+> (new image) recreates the container, which clears its logs.
+
 ---
 
 #### Local Access