ref/go: collapse dead circl-anchor placeholders, drop empty-slice append patterns

ref/go/pkg/pulsar/abort.go

@@ -317,8 +317,7 @@ func TranscriptForComplaint(e *AbortEvidence) []byte {
 	binary.BigEndian.PutUint64(epochBuf[:], e.Epoch)
 	parts = append(parts, epochBuf[:])
 	parts = append(parts, e.Evidence)
-	out := []byte{}
-	out = append(out, leftEncode(uint64(len(parts)))...)
+	out := append([]byte{}, leftEncode(uint64(len(parts)))...)
 	for _, p := range parts {
 		out = append(out, encodeString(p)...)
 	}

ref/go/pkg/pulsar/dkg.go

@@ -221,7 +221,7 @@ func (s *DKGSession) Round1() (*DKGRound1Msg, error) {
 	// blind_i material which existed only to feed the dropped
 	// commit-and-open layer.
 	committeeRoot := s.commitCommitteeRoot()
-	keyMaterial := []byte{}
+	keyMaterial := make([]byte, 0, len("PULSAR-DKG-DEALER-V1")+len(committeeRoot)+2+SeedSize)
 	keyMaterial = append(keyMaterial, []byte("PULSAR-DKG-DEALER-V1")...)
 	keyMaterial = append(keyMaterial, committeeRoot[:]...)
 	keyMaterial = append(keyMaterial, byte(s.myIndex>>8), byte(s.myIndex))

ref/go/pkg/pulsar/large_dkg.go

@@ -171,7 +171,7 @@ func (s *LargeDKGSession) Round1() (*LargeDKGRound1Msg, error) {
 	// derived seed) so two DKG sessions on the same contribution
 	// never collide.
 	committeeRoot := s.commitCommitteeRoot()
-	keyMaterial := []byte{}
+	keyMaterial := make([]byte, 0, len("PULSAR-DKG-DEALER-V1")+len(committeeRoot)+2+SeedSize)
 	keyMaterial = append(keyMaterial, []byte("PULSAR-DKG-DEALER-V1")...)
 	keyMaterial = append(keyMaterial, committeeRoot[:]...)
 	keyMaterial = append(keyMaterial, byte(s.myIndex>>8), byte(s.myIndex))

ref/go/pkg/pulsar/large_reshare.go

@@ -209,7 +209,7 @@ func (s *LargeReshareSession) Round1() (*LargeDKGRound1Msg, error) {
 		return nil, ErrShortRand
 	}
 
-	keyMaterial := []byte{}
+	keyMaterial := make([]byte, 0, len("PULSAR-RESHARE-DEALER-V1")+64+len(blind))
 	keyMaterial = append(keyMaterial, []byte("PULSAR-RESHARE-DEALER-V1")...)
 	keyMaterial = append(keyMaterial, s.commitOldCommitteeRoot()...)
 	keyMaterial = append(keyMaterial, s.commitNewCommitteeRoot()...)

ref/go/pkg/pulsar/reshare.go

@@ -281,7 +281,7 @@ func (s *ReshareSession) Round1() (*DKGRound1Msg, error) {
 	}
 
 	// Shamir-share the contribution at threshold newT to the new committee.
-	keyMaterial := []byte{}
+	keyMaterial := make([]byte, 0, len("PULSAR-RESHARE-DEALER-V1")+64+len(blind))
 	keyMaterial = append(keyMaterial, []byte("PULSAR-RESHARE-DEALER-V1")...)
 	keyMaterial = append(keyMaterial, s.commitOldCommitteeRoot()...)
 	keyMaterial = append(keyMaterial, s.commitNewCommitteeRoot()...)

ref/go/pkg/pulsar/threshold_v02.go

@@ -115,9 +115,6 @@ import (
 	"io"
 	"sort"
 
-	"github.com/cloudflare/circl/sign/mldsa/mldsa44"
-	"github.com/cloudflare/circl/sign/mldsa/mldsa65"
-	"github.com/cloudflare/circl/sign/mldsa/mldsa87"
 	"golang.org/x/crypto/sha3"
 )
 
@@ -1174,14 +1171,6 @@ func TransitionalAggregate(
 	return &Signature{Mode: params.Mode, Bytes: sigBytes}, nil
 }
 
-// ensureCirclLinked is a marker that pins the circl imports referenced
-// indirectly by mldsaSign through Sign in sign.go. Without this anchor
-// a future automated import cleanup could drop the explicit circl
-// dependencies threshold_v02.go relies on through the dispatch table.
-var _ = mldsa44.SignatureSize
-var _ = mldsa65.SignatureSize
-var _ = mldsa87.SignatureSize
-
 // algTranscriptTau1 builds the Round-1 transcript τ_1 for v0.2. Same
 // structure as v0.1's transcriptTau1Bytes but uses tagAlgR1 customisation
 // (callers feed this into the cSHAKE256/KMAC256 customisation field).
@@ -1209,10 +1198,10 @@ func algTranscriptTau1(sid [16]byte, attempt uint32, quorum []NodeID, sender Nod
 // per-party payload. MAC is taken over this transcript so any tamper
 // in (W, Z, CS2, CT0) flips the MAC.
 func algTranscriptTau2(sid [16]byte, attempt uint32, quorum []NodeID, sender NodeID, pk *PublicKey, message, w, z, cs2, ct0 []byte) []byte {
-	parts := [][]byte{}
-	parts = append(parts, []byte("ALG-V1-R2"))
-	parts = append(parts, sid[:])
-	parts = append(parts, []byte{byte(attempt >> 24), byte(attempt >> 16), byte(attempt >> 8), byte(attempt)})
+	var attemptBE [4]byte
+	binary.BigEndian.PutUint32(attemptBE[:], attempt)
+	parts := make([][]byte, 0, 8+len(quorum)+1)
+	parts = append(parts, []byte("ALG-V1-R2"), sid[:], attemptBE[:])
 	for _, q := range quorum {
 		parts = append(parts, q[:])
 	}
@@ -1220,13 +1209,8 @@ func algTranscriptTau2(sid [16]byte, attempt uint32, quorum []NodeID, sender Nod
 	if pk != nil {
 		parts = append(parts, pk.Bytes)
 	}
-	parts = append(parts, message)
-	parts = append(parts, w)
-	parts = append(parts, z)
-	parts = append(parts, cs2)
-	parts = append(parts, ct0)
-	out := []byte{}
-	out = append(out, leftEncode(uint64(len(parts)))...)
+	parts = append(parts, message, w, z, cs2, ct0)
+	out := append([]byte{}, leftEncode(uint64(len(parts)))...)
 	for _, p := range parts {
 		out = append(out, encodeString(p)...)
 	}

ref/go/pkg/pulsar/threshold_v03.go

@@ -134,9 +134,6 @@ import (
 	"io"
 	"sort"
 
-	"github.com/cloudflare/circl/sign/mldsa/mldsa44"
-	"github.com/cloudflare/circl/sign/mldsa/mldsa65"
-	"github.com/cloudflare/circl/sign/mldsa/mldsa87"
 	"golang.org/x/crypto/sha3"
 )
 
@@ -1162,10 +1159,10 @@ func algV03TranscriptTau1(sid [16]byte, attempt uint32, quorum []NodeID, sender
 // per-party payload. MAC is taken over this transcript so any tamper
 // in (W, Z, CS2, CT0) flips the MAC.
 func algV03TranscriptTau2(sid [16]byte, attempt uint32, quorum []NodeID, sender NodeID, pk *PublicKey, message, w, z, cs2, ct0 []byte) []byte {
-	parts := [][]byte{}
-	parts = append(parts, []byte("V03-R2"))
-	parts = append(parts, sid[:])
-	parts = append(parts, []byte{byte(attempt >> 24), byte(attempt >> 16), byte(attempt >> 8), byte(attempt)})
+	var attemptBE [4]byte
+	binary.BigEndian.PutUint32(attemptBE[:], attempt)
+	parts := make([][]byte, 0, 8+len(quorum)+1)
+	parts = append(parts, []byte("V03-R2"), sid[:], attemptBE[:])
 	for _, q := range quorum {
 		parts = append(parts, q[:])
 	}
@@ -1173,13 +1170,8 @@ func algV03TranscriptTau2(sid [16]byte, attempt uint32, quorum []NodeID, sender
 	if pk != nil {
 		parts = append(parts, pk.Bytes)
 	}
-	parts = append(parts, message)
-	parts = append(parts, w)
-	parts = append(parts, z)
-	parts = append(parts, cs2)
-	parts = append(parts, ct0)
-	out := []byte{}
-	out = append(out, leftEncode(uint64(len(parts)))...)
+	parts = append(parts, message, w, z, cs2, ct0)
+	out := append([]byte{}, leftEncode(uint64(len(parts)))...)
 	for _, p := range parts {
 		out = append(out, encodeString(p)...)
 	}
@@ -1204,16 +1196,3 @@ func V03QuorumEvalPoints(quorum []NodeID, shares []*AlgebraicKeyShare) ([]uint32
 	}
 	return out, nil
 }
-
-// ensureV03CirclLinked pins the circl imports so a future automated
-// import cleanup does not drop them. v0.3 does NOT call mldsaSign or
-// circl SignTo at any point — the imports are kept ONLY because
-// (a) Verify code paths reference these packages elsewhere in the file
-// and (b) the test suite needs them for byte-validity checks.
-var _ = mldsa44.SignatureSize
-var _ = mldsa65.SignatureSize
-var _ = mldsa87.SignatureSize
-
-// Ensure encoding/binary is imported (used by the test fixture pack/
-// unpack helpers and indirectly by polyDeriveUniformBall).
-var _ = binary.LittleEndian