feat: add agent runtime skeleton

scripts/worker-entrypoint.sh

@@ -1,5 +1,21 @@
 #!/usr/bin/env sh
 set -eu
 
-echo "HWLAB worker entrypoint placeholder"
+repo_root="$(CDPATH= cd -- "$(dirname -- "$0")/.." && pwd)"
+workspace_root="${HWLAB_WORKSPACE_ROOT:-/workspace}"
+agent_session_id="${HWLAB_AGENT_SESSION_ID:-agent_local}"
+project_id="${HWLAB_PROJECT_ID:-prj_local}"
+skill_commit_id="${HWLAB_SKILL_COMMIT_ID:-}"
+
+mkdir -p "$workspace_root"
+
+echo "HWLAB worker starting"
+echo "repo=$repo_root"
+echo "workspace=$workspace_root"
+echo "agentSessionId=$agent_session_id"
+echo "projectId=$project_id"
+if [ -n "$skill_commit_id" ]; then
+  echo "skillsCommitId=$skill_commit_id"
+fi
+
 exec "$@"