feat(proto): OpenDM RPC + gateway arm; GROUP_DM retirement; DM/convert fields (RIG-2962)

go/internal/auth/admin_gate.go

@@ -109,6 +109,7 @@ func classifyProcedure(procedure string) (privilege, bool) {
 		compassv1connect.CommsServiceSetChannelPolicyProcedure,
 		compassv1connect.CommsServiceGetRosterProcedure,
 		compassv1connect.CommsServiceUpdatePinnedBoardProcedure,
+		compassv1connect.CommsServiceOpenDMProcedure,
 		compassv1connect.CommsServiceSubscribeCommsProcedure:
 		return authenticatedOpen{}, true
 

go/internal/comms/channel_mapping_test.go

@@ -0,0 +1,65 @@
+// The channel-kind discriminant at the store <-> proto edge (mapping.go
+// channelKindToWire / channelKindFromWire). Both are pure functions of their
+// argument, so the contract is fully observable with NO database — this file is
+// untagged and runs on the default `go test` lane.
+//
+// GROUP_DM retirement (RIG-2962 T1): the kind is deprecated in place — never
+// PRODUCED on either side. A DM widens by converting to a named CHANNEL, so no
+// mapping arm may mint a GROUP_DM. The number stays reserved (tombstone), but a
+// legacy or hostile GROUP_DM input collapses to a plain channel rather than
+// round-tripping the retired kind.
+
+package comms
+
+import (
+	"testing"
+
+	compassv1 "github.com/RigelBuild/compass/go/gen/compass/v1"
+	"github.com/RigelBuild/compass/go/internal/store"
+)
+
+func TestChannelKindToWireNeverProducesGroupDM(t *testing.T) {
+	tests := []struct {
+		name string
+		kind store.ChannelKind
+		want compassv1.ChannelKind
+	}{
+		{"channel", store.ChannelKindChannel, compassv1.ChannelKind_CHANNEL_KIND_CHANNEL},
+		{"dm", store.ChannelKindDM, compassv1.ChannelKind_CHANNEL_KIND_DM},
+		{"retired group_dm collapses to channel", store.ChannelKindGroupDM, compassv1.ChannelKind_CHANNEL_KIND_CHANNEL},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := channelKindToWire(tt.kind)
+			if got != tt.want {
+				t.Fatalf("channelKindToWire(%v) = %v, want %v", tt.kind, got, tt.want)
+			}
+			if got == compassv1.ChannelKind_CHANNEL_KIND_GROUP_DM { //nolint:staticcheck // SA1019: deliberately references the retired GROUP_DM to assert it is never produced.
+				t.Fatalf("channelKindToWire produced retired GROUP_DM for %v", tt.kind)
+			}
+		})
+	}
+}
+
+func TestChannelKindFromWireNeverProducesGroupDM(t *testing.T) {
+	tests := []struct {
+		name string
+		kind compassv1.ChannelKind
+		want store.ChannelKind
+	}{
+		{"channel", compassv1.ChannelKind_CHANNEL_KIND_CHANNEL, store.ChannelKindChannel},
+		{"dm", compassv1.ChannelKind_CHANNEL_KIND_DM, store.ChannelKindDM},
+		{"retired group_dm collapses to channel", compassv1.ChannelKind_CHANNEL_KIND_GROUP_DM, store.ChannelKindChannel}, //nolint:staticcheck // SA1019: deliberately exercises the retired GROUP_DM input path.
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := channelKindFromWire(tt.kind)
+			if got != tt.want {
+				t.Fatalf("channelKindFromWire(%v) = %v, want %v", tt.kind, got, tt.want)
+			}
+			if got == store.ChannelKindGroupDM {
+				t.Fatalf("channelKindFromWire produced retired GROUP_DM for %v", tt.kind)
+			}
+		})
+	}
+}

go/internal/comms/comms.go

@@ -635,6 +635,21 @@ func (c *Comms) UpdatePinnedBoard(
 	return connect.NewResponse(&compassv1.UpdatePinnedBoardResponse{Channel: wire}), nil
 }
 
+// OpenDM resolves-or-creates the two-party DM channel between the caller and a
+// peer, addressed by handle (RIG-2962). T1 lands the contract (proto + regen)
+// proto-first; the real handler — caller/peer resolve, same-owner authz, the
+// reserved-DM-group upsert, and the post-commit ChannelChanged emit — is the
+// T3 leg (compass-agent-peer-dm design.md T3), which replaces this stub. Until
+// then it returns CodeUnimplemented so *Comms satisfies the generated
+// CommsServiceHandler (asserted with no Unimplemented embed) without pretending
+// to serve a surface whose store legs (T2 dm.go) do not exist yet.
+func (c *Comms) OpenDM(
+	_ context.Context,
+	_ *connect.Request[compassv1.OpenDMRequest],
+) (*connect.Response[compassv1.OpenDMResponse], error) {
+	return nil, connect.NewError(connect.CodeUnimplemented, errors.New("comms: OpenDM not implemented until RIG-2962 T3"))
+}
+
 // applyBoardOp maps the request's op oneof to its store call: a plain pin
 // (PinMessage, replace ""), a compare-and-swap repoint (PinMessage, replace set),
 // or an unpin (UnpinMessage). An unset oneof is a malformed request

go/internal/comms/mapping.go

@@ -82,9 +82,9 @@ func channelKindToWire(k store.ChannelKind) compassv1.ChannelKind {
 	switch k {
 	case store.ChannelKindDM:
 		return compassv1.ChannelKind_CHANNEL_KIND_DM
-	case store.ChannelKindGroupDM:
-		return compassv1.ChannelKind_CHANNEL_KIND_GROUP_DM
 	default:
+		// GROUP_DM is retired (never produced; a DM converts to a named
+		// CHANNEL). A legacy kind=2 row renders as a plain channel.
 		return compassv1.ChannelKind_CHANNEL_KIND_CHANNEL
 	}
 }
@@ -256,9 +256,11 @@ func channelKindFromWire(k compassv1.ChannelKind) store.ChannelKind {
 	switch k {
 	case compassv1.ChannelKind_CHANNEL_KIND_DM:
 		return store.ChannelKindDM
-	case compassv1.ChannelKind_CHANNEL_KIND_GROUP_DM:
-		return store.ChannelKindGroupDM
 	default:
+		// GROUP_DM is retired: a wire GROUP_DM (only a legacy/hostile input,
+		// never freshly produced) maps to a plain channel. The collapse itself
+		// is the sole retirement mechanism at this edge — the retired kind can
+		// never round-trip into the store.
 		return store.ChannelKindChannel
 	}
 }