fix: carry immutable hash in command dispatch

internal/server/session/agent_server.go

@@ -257,7 +257,7 @@ func (server *AgentServer) enqueueNextDispatch(ctx context.Context, queue *Write
 	}
 	dispatch := &rvboxv1.CommandDispatch{
 		IssueUuid: candidate.IssueUUID.String(), CommandRevision: candidate.Revision, TargetSessionGeneration: generation,
-		IssueTime: timestamppb.New(candidate.IssueTime), Spec: spec,
+		IssueTime: timestamppb.New(candidate.IssueTime), Spec: spec, ImmutableRequestSha256: candidate.ImmutableSHA256[:],
 	}
 	if candidate.QueueExpiryTime != nil {
 		dispatch.QueueExpiryTime = timestamppb.New(*candidate.QueueExpiryTime)

internal/server/store/dispatch.go

@@ -23,6 +23,7 @@ type DispatchCandidate struct {
 	Revision        uint64
 	IssueTime       time.Time
 	QueueExpiryTime *time.Time
+	ImmutableSHA256 [32]byte
 	ExecutionSpec   []byte
 }
 
@@ -51,13 +52,13 @@ func (store *Store) ClaimNextDispatch(ctx context.Context, clientID string, gene
 WHERE client_id = ? AND lifecycle = 1 AND queue_expiry_time IS NOT NULL AND queue_expiry_time <= ?`, now.UTC().UnixNano(), clientID, now.UTC().UnixNano()); err != nil {
 		return nil, err
 	}
-	var encodedIssue, stored []byte
+	var encodedIssue, stored, immutableHash []byte
 	var revision uint64
 	var issueTime int64
 	var expiry sql.NullInt64
 	var rawBytes uint64
-	err = tx.QueryRowContext(ctx, `SELECT issue_uuid, revision, issue_time, queue_expiry_time, execution_spec, execution_spec_raw_bytes
-FROM commands WHERE client_id = ? AND lifecycle = 1 ORDER BY issue_time, issue_uuid LIMIT 1`, clientID).Scan(&encodedIssue, &revision, &issueTime, &expiry, &stored, &rawBytes)
+	err = tx.QueryRowContext(ctx, `SELECT issue_uuid, revision, issue_time, queue_expiry_time, immutable_request_sha256, execution_spec, execution_spec_raw_bytes
+FROM commands WHERE client_id = ? AND lifecycle = 1 ORDER BY issue_time, issue_uuid LIMIT 1`, clientID).Scan(&encodedIssue, &revision, &issueTime, &expiry, &immutableHash, &stored, &rawBytes)
 	if errors.Is(err, sql.ErrNoRows) {
 		if err := tx.Commit(); err != nil {
 			return nil, err
@@ -67,11 +68,13 @@ FROM commands WHERE client_id = ? AND lifecycle = 1 ORDER BY issue_time, issue_u
 	if err != nil {
 		return nil, err
 	}
-	if len(encodedIssue) != 16 {
+	if len(encodedIssue) != 16 || len(immutableHash) != 32 {
 		return nil, ErrInvalidSegmentRecord
 	}
 	var issue domain.UUID
 	copy(issue[:], encodedIssue)
+	var immutable [32]byte
+	copy(immutable[:], immutableHash)
 	spec, err := decompressCommandSpec(stored, rawBytes)
 	if err != nil {
 		return nil, err
@@ -90,7 +93,7 @@ FROM commands WHERE client_id = ? AND lifecycle = 1 ORDER BY issue_time, issue_u
 	if err := tx.Commit(); err != nil {
 		return nil, err
 	}
-	candidate := &DispatchCandidate{IssueUUID: issue, Revision: revision, IssueTime: time.Unix(0, issueTime).UTC(), ExecutionSpec: spec}
+	candidate := &DispatchCandidate{IssueUUID: issue, Revision: revision, IssueTime: time.Unix(0, issueTime).UTC(), ImmutableSHA256: immutable, ExecutionSpec: spec}
 	if expiry.Valid {
 		value := time.Unix(0, expiry.Int64).UTC()
 		candidate.QueueExpiryTime = &value