feat(craft): persist opencode session data across sandbox sleep/wake

Move opencode's session storage from container-local ~/.local/share/ to
the shared workspace volume via XDG_DATA_HOME. This ensures session data
is captured in snapshots and restored on wake, allowing ephemeral ACP
clients to resume conversation context after sleep/wake cycles.

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

Author: rohoswagger

backend/onyx/server/features/build/sandbox/kubernetes/internal/acp_exec_client.py

@@ -21,6 +21,7 @@
 """
 
 import json
+import shlex
 import threading
 import time
 from collections.abc import Generator
@@ -175,8 +176,17 @@ def start(self, cwd: str = "/workspace", timeout: float = 30.0) -> None:
 
         k8s = self._get_k8s_client()
 
-        # Start opencode acp via exec
-        exec_command = ["opencode", "acp", "--cwd", cwd]
+        # Start opencode acp via exec.
+        # Set XDG_DATA_HOME so opencode stores session data on the shared
+        # workspace volume (accessible from file-sync container for snapshots)
+        # instead of the container-local ~/.local/share/ filesystem.
+        data_dir = shlex.quote(f"{cwd}/.opencode-data")
+        safe_cwd = shlex.quote(cwd)
+        exec_command = [
+            "/bin/sh",
+            "-c",
+            f"XDG_DATA_HOME={data_dir} exec opencode acp --cwd {safe_cwd}",
+        ]
 
         logger.info(f"[ACP] Starting client: pod={self._pod_name} cwd={cwd}")
 

backend/onyx/server/features/build/sandbox/kubernetes/kubernetes_sandbox_manager.py

@@ -1472,6 +1472,7 @@ def create_snapshot(
         the snapshot and upload to S3. Captures:
         - sessions/$session_id/outputs/ (generated artifacts, web apps)
         - sessions/$session_id/attachments/ (user uploaded files)
+        - sessions/$session_id/.opencode-data/ (opencode session data for resumption)
 
         Args:
             sandbox_id: The sandbox ID
@@ -1496,9 +1497,10 @@ def create_snapshot(
             f"{session_id_str}/{snapshot_id}.tar.gz"
         )
 
-        # Exec into pod to create and upload snapshot (outputs + attachments)
-        # Uses s5cmd pipe to stream tar.gz directly to S3
-        # Only snapshot if outputs/ exists. Include attachments/ only if non-empty.
+        # Create tar and upload to S3 via file-sync container.
+        # .opencode-data/ is already on the shared workspace volume because we set
+        # XDG_DATA_HOME to the session directory when starting opencode (see
+        # ACPExecClient.start()). No cross-container copy needed.
         exec_command = [
             "/bin/sh",
             "-c",
@@ -1511,6 +1513,7 @@ def create_snapshot(
 fi
 dirs="outputs"
 [ -d attachments ] && [ "$(ls -A attachments 2>/dev/null)" ] && dirs="$dirs attachments"
+[ -d .opencode-data ] && [ "$(ls -A .opencode-data 2>/dev/null)" ] && dirs="$dirs .opencode-data"
 tar -czf - $dirs | /s5cmd pipe {s3_path}
 echo "SNAPSHOT_CREATED"
 """,
@@ -1632,6 +1635,7 @@ def restore_snapshot(
         Steps:
         1. Exec s5cmd cat in file-sync container to stream snapshot from S3
         2. Pipe directly to tar for extraction in the shared workspace volume
+           (.opencode-data/ is restored automatically since XDG_DATA_HOME points here)
         3. Regenerate configuration files (AGENTS.md, opencode.json, files symlink)
         4. Start the NextJS dev server