android: V4.9 + V4.10 Kotlin ports + KeystoreStorage adapter

Pure-JVM additions to shade-android (no Android SDK needed):
- V4.9 blob primitives: BlobKdf (HKDF deriveBlobSlotId/Key/SigningSeed),
  BlobAead (nonce||ct||tag with shade-profile-aad-v1:<slot> AAD),
  BlobClient (java.net.http with hand-written canonical JSON signing
  matching TS signPayload output), Profile high-level namespace.
- V4.10 approval helpers: CanonicalProfileBlob schema with denormalized
  trustedApproverFingerprints, build/sign/verify proxy approvals via
  length-prefixed u16 BE UTF-8 canonical signing payload.
- Password KDFs: scrypt + argon2id via Bouncy Castle, NFKC-normalized.
- SessionStateJson at-rest serializer for persistence layer.

Cross-platform vectors (test-vectors/blob.json, approval.json) gate
byte-identical output between TS and Kotlin, including a TS-signed
Ed25519 signature the Kotlin port verifies and reproduces (Ed25519 is
deterministic).

New shade-android-keystore sibling Gradle module (Android-specific):
- KeystoreMasterKey: hardware-backed AES-256-GCM with BIOMETRIC_STRONG
  gating, StrongBox-backed when available, invalidated on enrollment.
- BiometricUnlock: coroutine wrapper around BiometricPrompt with
  tagged cancellation/failure exceptions.
- KeystoreStorage: StorageProvider over biometric-gated AES-encrypted
  SharedPreferences with AAD-bound row keys.

All 25 SDK packages typecheck clean; 104 SDK tests + 24 new Kotlin
tests + 11 cross-platform vector tests all green.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

android/shade-android/src/test/kotlin/no/zyon/shade/BlobAndApprovalTest.kt

@@ -0,0 +1,593 @@
+package no.zyon.shade
+
+import no.zyon.shade.approval.ApprovalRequestFrame
+import no.zyon.shade.approval.ApprovalRequestingDevice
+import no.zyon.shade.approval.CanonicalProfileBlob
+import no.zyon.shade.approval.DEFAULT_APPROVAL_DOMAIN
+import no.zyon.shade.approval.ProfileClientEntry
+import no.zyon.shade.approval.ProfileHostEntry
+import no.zyon.shade.approval.ProxyApprovalFrame
+import no.zyon.shade.approval.VerifyProxyApprovalResult
+import no.zyon.shade.approval.buildApprovalRequest
+import no.zyon.shade.approval.canonicalApprovalSigningBytes
+import no.zyon.shade.approval.emptyCanonicalProfile
+import no.zyon.shade.approval.findClientByAddress
+import no.zyon.shade.approval.findClientByFingerprint
+import no.zyon.shade.approval.isTrustedApprover
+import no.zyon.shade.approval.parseCanonicalProfile
+import no.zyon.shade.approval.removeClient
+import no.zyon.shade.approval.serializeCanonicalProfile
+import no.zyon.shade.approval.setTrustedApprover
+import no.zyon.shade.approval.signProxyApproval
+import no.zyon.shade.approval.upsertClient
+import no.zyon.shade.approval.upsertHost
+import no.zyon.shade.approval.verifyProxyApproval
+import no.zyon.shade.blob.aeadOpen
+import no.zyon.shade.blob.aeadSeal
+import no.zyon.shade.blob.blobAadForSlot
+import no.zyon.shade.blob.deriveBlobKey
+import no.zyon.shade.blob.deriveBlobSigningSeed
+import no.zyon.shade.blob.deriveBlobSlotId
+import no.zyon.shade.blob.ed25519PublicKeyFromSeed
+import no.zyon.shade.blob.slotIdToHex
+import no.zyon.shade.crypto.TinkProvider
+import no.zyon.shade.storage.Argon2idParams
+import no.zyon.shade.storage.ScryptParams
+import no.zyon.shade.storage.deriveMasterKey
+import no.zyon.shade.storage.deriveMasterKeyArgon2id
+import org.junit.Assert.assertArrayEquals
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertFalse
+import org.junit.Assert.assertNotNull
+import org.junit.Assert.assertNull
+import org.junit.Assert.assertNotEquals
+import org.junit.Assert.assertTrue
+import org.junit.Test
+
+/**
+ * Unit tests for the V4.9 blob primitive ports + V4.10 approval
+ * helpers + scrypt/argon2id wrappers. Cross-platform vector parity
+ * lives in `CrossPlatformVectorTest`; this file tests Kotlin-side
+ * round-trip behavior independent of the TS reference.
+ */
+class BlobAndApprovalTest {
+
+    private val crypto = TinkProvider()
+
+    private fun hex(bytes: ByteArray): String =
+        bytes.joinToString("") { "%02x".format(it) }
+
+    // ─── V4.9 blob KDF ─────────────────────────────────────────
+
+    @Test
+    fun deriveBlobSlotIdIsDeterministicPerMasterAndApp() {
+        val km = ByteArray(32) { it.toByte() }
+        val a1 = deriveBlobSlotId(crypto, km, "foo")
+        val a2 = deriveBlobSlotId(crypto, km, "foo")
+        assertArrayEquals(a1, a2)
+
+        val b = deriveBlobSlotId(crypto, km, "bar")
+        assertFalse(a1.contentEquals(b))
+
+        val km2 = ByteArray(32) { (it + 1).toByte() }
+        val c = deriveBlobSlotId(crypto, km2, "foo")
+        assertFalse(a1.contentEquals(c))
+    }
+
+    @Test
+    fun blobKdfHelpersAreIndependent() {
+        val km = ByteArray(32) { it.toByte() }
+        val slot = deriveBlobSlotId(crypto, km, "x")
+        val key = deriveBlobKey(crypto, km, "x")
+        val seed = deriveBlobSigningSeed(crypto, km, "x")
+        assertFalse(slot.contentEquals(key))
+        assertFalse(slot.contentEquals(seed))
+        assertFalse(key.contentEquals(seed))
+    }
+
+    @Test
+    fun ed25519PublicKeyFromSeedIsDeterministic() {
+        val seed = ByteArray(32) { it.toByte() }
+        val pk1 = ed25519PublicKeyFromSeed(seed)
+        val pk2 = ed25519PublicKeyFromSeed(seed)
+        assertArrayEquals(pk1, pk2)
+        assertEquals(32, pk1.size)
+    }
+
+    @Test
+    fun slotIdToHexProducesLowercase64Chars() {
+        val s = ByteArray(32) { 0xab.toByte() }
+        val hex = slotIdToHex(s)
+        assertEquals(64, hex.length)
+        assertEquals("a".repeat(0) + "ab".repeat(32), hex)
+    }
+
+    // ─── V4.9 AEAD round-trip ──────────────────────────────────
+
+    @Test
+    fun aeadSealOpenRoundTrip() {
+        val key = crypto.randomBytes(32)
+        val nonce = crypto.randomBytes(12)
+        val pt = "hello".toByteArray()
+        val aad = blobAadForSlot("00".repeat(32))
+        val sealed = aeadSeal(key, nonce, pt, aad)
+        val opened = aeadOpen(key, sealed, aad)
+        assertArrayEquals(pt, opened)
+    }
+
+    @Test
+    fun aeadOpenWithWrongAadFails() {
+        val key = crypto.randomBytes(32)
+        val nonce = crypto.randomBytes(12)
+        val pt = "hello".toByteArray()
+        val aad1 = blobAadForSlot("00".repeat(32))
+        val aad2 = blobAadForSlot("ff".repeat(32))
+        val sealed = aeadSeal(key, nonce, pt, aad1)
+        try {
+            aeadOpen(key, sealed, aad2)
+            org.junit.Assert.fail("expected AEAD to reject wrong AAD")
+        } catch (_: Exception) {
+            // expected
+        }
+    }
+
+    @Test
+    fun aeadOpenWithExpectedNonceMismatchFails() {
+        val key = crypto.randomBytes(32)
+        val nonce = crypto.randomBytes(12)
+        val wrongNonce = crypto.randomBytes(12)
+        val pt = "hello".toByteArray()
+        val aad = blobAadForSlot("00".repeat(32))
+        val sealed = aeadSeal(key, nonce, pt, aad)
+        try {
+            aeadOpen(key, sealed, aad, expectedNonce = wrongNonce)
+            org.junit.Assert.fail("expected expectedNonce check to reject")
+        } catch (_: IllegalArgumentException) {
+            // expected
+        }
+    }
+
+    // ─── Password KDFs ─────────────────────────────────────────
+
+    @Test
+    fun scryptDerivesDeterministically() {
+        val pw = "correct-horse-battery-staple"
+        val salt = ByteArray(16) { 0x42.toByte() }
+        val k1 = deriveMasterKey(pw, salt, ScryptParams(n = 1024))
+        val k2 = deriveMasterKey(pw, salt, ScryptParams(n = 1024))
+        assertArrayEquals(k1, k2)
+        assertEquals(32, k1.size)
+    }
+
+    @Test
+    fun argon2idDerivesDeterministically() {
+        val pw = "1234"
+        val salt = ByteArray(16) { 0x55.toByte() }
+        val k1 = deriveMasterKeyArgon2id(pw, salt, Argon2idParams(m = 256, t = 2))
+        val k2 = deriveMasterKeyArgon2id(pw, salt, Argon2idParams(m = 256, t = 2))
+        assertArrayEquals(k1, k2)
+        assertEquals(32, k1.size)
+    }
+
+    @Test
+    fun nfkcNormalizationMakesEquivalentInputsConverge() {
+        // "café" can be encoded either as 'c','a','f','é' (NFC) or
+        // 'c','a','f','e','́' (NFD). NFKC normalization on both
+        // should converge to the same bytes.
+        val nfc = "café"
+        val nfd = "café"
+        assertNotEquals(nfc, nfd)
+        val salt = ByteArray(16) { 1.toByte() }
+        val k1 = deriveMasterKey(nfc, salt, ScryptParams(n = 1024))
+        val k2 = deriveMasterKey(nfd, salt, ScryptParams(n = 1024))
+        assertArrayEquals(k1, k2)
+    }
+
+    // ─── Canonical profile schema ──────────────────────────────
+
+    private fun makeClient(name: String, trusted: Boolean = false): Pair<ProfileClientEntry, ByteArray> {
+        val seed = crypto.randomBytes(32)
+        val pubkey = ed25519PublicKeyFromSeed(seed)
+        val fp = "fp-$name-${hex(pubkey).take(8)}"
+        return ProfileClientEntry(
+            address = "device:$name",
+            identityPublicKey = hex(pubkey),
+            identityFingerprint = fp,
+            name = name,
+            kind = "mobile",
+            addedAt = 1_700_000_000_000L,
+            trustedApprover = trusted,
+        ) to seed
+    }
+
+    private fun makeHost(): ProfileHostEntry = ProfileHostEntry(
+        address = "device:host-server",
+        name = "Server",
+        kind = "server",
+        addedAt = 1_700_000_000_000L,
+    )
+
+    @Test
+    fun emptyCanonicalProfileRoundTrips() {
+        val blob = emptyCanonicalProfile(now = 123L)
+        val bytes = serializeCanonicalProfile(blob)
+        val parsed = parseCanonicalProfile(bytes)
+        assertEquals(1, parsed.version)
+        assertTrue(parsed.hosts.isEmpty())
+        assertTrue(parsed.clients.isEmpty())
+        assertTrue(parsed.trustedApproverFingerprints.isEmpty())
+        assertEquals(123L, parsed.updatedAt)
+    }
+
+    @Test
+    fun upsertClientDenormalizesTrustedApprovers() {
+        var blob = emptyCanonicalProfile(0)
+        val (a, _) = makeClient("phone-a", trusted = true)
+        val (b, _) = makeClient("phone-b", trusted = false)
+        blob = upsertClient(blob, a)
+        blob = upsertClient(blob, b)
+        assertEquals(2, blob.clients.size)
+        assertEquals(listOf(a.identityFingerprint), blob.trustedApproverFingerprints)
+        assertTrue(isTrustedApprover(blob, a.identityFingerprint))
+        assertFalse(isTrustedApprover(blob, b.identityFingerprint))
+    }
+
+    @Test
+    fun setTrustedApproverIsIdempotentNoOpReturnsSameInstance() {
+        var blob = emptyCanonicalProfile(0)
+        val (c, _) = makeClient("phone", trusted = false)
+        blob = upsertClient(blob, c)
+        val before = blob
+        blob = setTrustedApprover(blob, c.identityFingerprint, false, now = 999L)
+        assertTrue(blob === before)
+    }
+
+    @Test
+    fun setTrustedApproverFlipsFlagAndDenormalizedList() {
+        var blob = emptyCanonicalProfile(0)
+        val (c, _) = makeClient("phone", trusted = false)
+        blob = upsertClient(blob, c)
+        blob = setTrustedApprover(blob, c.identityFingerprint, true, now = 100L)
+        assertEquals(listOf(c.identityFingerprint), blob.trustedApproverFingerprints)
+        assertEquals(true, blob.clients[0].trustedApprover)
+
+        blob = setTrustedApprover(blob, c.identityFingerprint, false, now = 200L)
+        assertTrue(blob.trustedApproverFingerprints.isEmpty())
+        assertEquals(false, blob.clients[0].trustedApprover)
+    }
+
+    @Test
+    fun removeClientCleansUpDenormalizedList() {
+        var blob = emptyCanonicalProfile(0)
+        val (c, _) = makeClient("phone", trusted = true)
+        blob = upsertClient(blob, c)
+        blob = removeClient(blob, c.identityFingerprint)
+        assertTrue(blob.clients.isEmpty())
+        assertTrue(blob.trustedApproverFingerprints.isEmpty())
+    }
+
+    @Test
+    fun findClientByFingerprintAndAddress() {
+        var blob = emptyCanonicalProfile(0)
+        val (c, _) = makeClient("phone")
+        blob = upsertClient(blob, c)
+        assertEquals(c.address, findClientByFingerprint(blob, c.identityFingerprint)?.address)
+        assertEquals(
+            c.identityFingerprint,
+            findClientByAddress(blob, c.address)?.identityFingerprint,
+        )
+        assertNull(findClientByFingerprint(blob, "unknown"))
+        assertNull(findClientByAddress(blob, "unknown"))
+    }
+
+    @Test
+    fun parseRejectsMalformedProfile() {
+        try {
+            parseCanonicalProfile("not json")
+            org.junit.Assert.fail("expected throw")
+        } catch (_: IllegalArgumentException) {}
+        try {
+            parseCanonicalProfile("""{"version":2}""")
+            org.junit.Assert.fail("expected throw")
+        } catch (_: IllegalArgumentException) {}
+        try {
+            parseCanonicalProfile(
+                """{"version":1,"clients":[{"address":"x","name":"x","kind":"m","addedAt":0}]}""",
+            )
+            org.junit.Assert.fail("expected throw — missing identityPublicKey")
+        } catch (_: IllegalArgumentException) {}
+        try {
+            parseCanonicalProfile(
+                """{"version":1,"clients":[{"address":"x","identityPublicKey":"NOTHEX","identityFingerprint":"x","name":"x","kind":"m","addedAt":0}]}""",
+            )
+            org.junit.Assert.fail("expected throw — bad pubkey hex")
+        } catch (_: IllegalArgumentException) {}
+    }
+
+    @Test
+    fun fullProfileSerializeParsePreservesAllFields() {
+        var blob = emptyCanonicalProfile(1L)
+        blob = upsertHost(blob, makeHost(), now = 2L)
+        val (c, _) = makeClient("phone", trusted = true)
+        blob = upsertClient(blob, c, now = 3L)
+        blob = blob.copy(signedBy = "aabbccdd")
+
+        val bytes = serializeCanonicalProfile(blob)
+        val parsed = parseCanonicalProfile(bytes)
+        assertEquals(blob, parsed)
+    }
+
+    // ─── Approval signing payload ──────────────────────────────
+
+    @Test
+    fun canonicalApprovalSigningBytesIsDeterministic() {
+        val a = canonicalApprovalSigningBytes(
+            domain = DEFAULT_APPROVAL_DOMAIN,
+            requestId = "aabbccddeeff00112233445566778899",
+            hostFingerprint = "11111 22222 33333 44444",
+            requestingDeviceFingerprint = "55555 66666 77777 88888",
+            decision = "approve",
+        )
+        val b = canonicalApprovalSigningBytes(
+            domain = DEFAULT_APPROVAL_DOMAIN,
+            requestId = "aabbccddeeff00112233445566778899",
+            hostFingerprint = "11111 22222 33333 44444",
+            requestingDeviceFingerprint = "55555 66666 77777 88888",
+            decision = "approve",
+        )
+        assertArrayEquals(a, b)
+    }
+
+    @Test
+    fun differentDecisionProducesDifferentSigningBytes() {
+        val approve = canonicalApprovalSigningBytes(
+            DEFAULT_APPROVAL_DOMAIN, "r", "h", "d", "approve",
+        )
+        val reject = canonicalApprovalSigningBytes(
+            DEFAULT_APPROVAL_DOMAIN, "r", "h", "d", "reject",
+        )
+        assertFalse(approve.contentEquals(reject))
+    }
+
+    @Test
+    fun differentDomainProducesDifferentSigningBytes() {
+        val a = canonicalApprovalSigningBytes("shade-link-approve-v1", "r", "h", "d", "approve")
+        val b = canonicalApprovalSigningBytes("prism-link-approve-v1", "r", "h", "d", "approve")
+        assertFalse(a.contentEquals(b))
+    }
+
+    // ─── Build / sign / verify ─────────────────────────────────
+
+    private data class Scenario(
+        val phone: ProfileClientEntry,
+        val phoneSeed: ByteArray,
+        val profile: CanonicalProfileBlob,
+        val request: ApprovalRequestFrame,
+    )
+
+    private fun buildScenario(): Scenario {
+        val (phone, seed) = makeClient("phone", trusted = true)
+        var profile = emptyCanonicalProfile(0)
+        profile = upsertHost(profile, makeHost())
+        profile = upsertClient(profile, phone)
+
+        val request = buildApprovalRequest(
+            crypto = crypto,
+            hostAddress = "device:host-server",
+            hostFingerprint = "host-fp-12345",
+            requestingDeviceFingerprint = "cafe-laptop-fp-67890",
+            deviceName = "cafe-laptop",
+            userAgent = "Mozilla/5.0",
+            ipHint = "203.0.113.7",
+        )
+        return Scenario(phone, seed, profile, request)
+    }
+
+    @Test
+    fun happyPathApproveVerifies() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request,
+            decision = "approve",
+            approverFingerprint = s.phone.identityFingerprint,
+            approverSigningKey = s.phoneSeed,
+        )
+        assertEquals("linkApproveByProxy", approval.kind)
+        assertEquals(s.request.requestId, approval.requestId)
+        assertEquals(128, approval.signature.length)
+
+        val r = verifyProxyApproval(crypto, s.request, approval, s.profile)
+        assertTrue(r is VerifyProxyApprovalResult.Ok)
+        assertEquals(s.phone.address, (r as VerifyProxyApprovalResult.Ok).approver.address)
+    }
+
+    @Test
+    fun happyPathRejectVerifies() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request, "reject",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        val r = verifyProxyApproval(crypto, s.request, approval, s.profile)
+        assertTrue(r is VerifyProxyApprovalResult.Ok)
+    }
+
+    @Test
+    fun replayAgainstDifferentRequestFails() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request, "approve",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        val other = s.request.copy(requestId = "f".repeat(32))
+        val r = verifyProxyApproval(crypto, other, approval, s.profile)
+        assertEquals(
+            VerifyProxyApprovalResult.Reason.REQUEST_ID_MISMATCH,
+            (r as VerifyProxyApprovalResult.Failed).reason,
+        )
+    }
+
+    @Test
+    fun decisionTamperingFails() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request, "approve",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        val tampered = approval.copy(decision = "reject")
+        val r = verifyProxyApproval(crypto, s.request, tampered, s.profile)
+        assertEquals(
+            VerifyProxyApprovalResult.Reason.BAD_SIGNATURE,
+            (r as VerifyProxyApprovalResult.Failed).reason,
+        )
+    }
+
+    @Test
+    fun hostFingerprintSwapFails() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request, "approve",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        val swapped = s.request.copy(hostFingerprint = "evil-host-fp")
+        val r = verifyProxyApproval(crypto, swapped, approval, s.profile)
+        assertEquals(
+            VerifyProxyApprovalResult.Reason.BAD_SIGNATURE,
+            (r as VerifyProxyApprovalResult.Failed).reason,
+        )
+    }
+
+    @Test
+    fun domainMismatchIsRejectedBeforeSignature() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request, "approve",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        val r = verifyProxyApproval(
+            crypto, s.request, approval.copy(domain = "prism-link-approve-v1"), s.profile,
+        )
+        assertEquals(
+            VerifyProxyApprovalResult.Reason.DOMAIN_MISMATCH,
+            (r as VerifyProxyApprovalResult.Failed).reason,
+        )
+    }
+
+    @Test
+    fun unknownApproverFails() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request, "approve",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        val lying = approval.copy(approverFingerprint = "no-such-fingerprint")
+        val r = verifyProxyApproval(crypto, s.request, lying, s.profile)
+        assertEquals(
+            VerifyProxyApprovalResult.Reason.UNKNOWN_APPROVER,
+            (r as VerifyProxyApprovalResult.Failed).reason,
+        )
+    }
+
+    @Test
+    fun revokedApproverFailsWithNotTrusted() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request, "approve",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        val revoked = setTrustedApprover(s.profile, s.phone.identityFingerprint, false)
+        val r = verifyProxyApproval(crypto, s.request, approval, revoked)
+        assertEquals(
+            VerifyProxyApprovalResult.Reason.NOT_TRUSTED,
+            (r as VerifyProxyApprovalResult.Failed).reason,
+        )
+    }
+
+    @Test
+    fun expiredRequestIsRejected() {
+        val s = buildScenario()
+        val approval = signProxyApproval(
+            crypto, s.request, "approve",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        val r = verifyProxyApproval(crypto, s.request, approval, s.profile, now = s.request.expiresAt + 1)
+        assertEquals(
+            VerifyProxyApprovalResult.Reason.EXPIRED,
+            (r as VerifyProxyApprovalResult.Failed).reason,
+        )
+    }
+
+    @Test
+    fun signatureWithWrongKeyFails() {
+        val s = buildScenario()
+        val wrongSeed = crypto.randomBytes(32)
+        val approval = signProxyApproval(
+            crypto, s.request, "approve",
+            approverFingerprint = s.phone.identityFingerprint, // claim phone
+            approverSigningKey = wrongSeed,                    // sign with different key
+        )
+        val r = verifyProxyApproval(crypto, s.request, approval, s.profile)
+        assertEquals(
+            VerifyProxyApprovalResult.Reason.BAD_SIGNATURE,
+            (r as VerifyProxyApprovalResult.Failed).reason,
+        )
+    }
+
+    @Test
+    fun customDomainSurvivesRoundTrip() {
+        val s = buildScenario()
+        val request = s.request.copy(domain = "prism-link-approve-v1")
+        val approval = signProxyApproval(
+            crypto, request, "approve",
+            s.phone.identityFingerprint, s.phoneSeed,
+        )
+        assertEquals("prism-link-approve-v1", approval.domain)
+        val r = verifyProxyApproval(crypto, request, approval, s.profile)
+        assertTrue(r is VerifyProxyApprovalResult.Ok)
+    }
+
+    @Test
+    fun requestIdIs32LowercaseHexChars() {
+        val r = buildApprovalRequest(
+            crypto, "device:h", "h", "r",
+        )
+        assertTrue(r.requestId.matches(Regex("^[0-9a-f]{32}$")))
+    }
+
+    @Test
+    fun consecutiveBuildsProduceDistinctRequestIds() {
+        val a = buildApprovalRequest(crypto, "device:h", "h", "r")
+        val b = buildApprovalRequest(crypto, "device:h", "h", "r")
+        assertNotEquals(a.requestId, b.requestId)
+    }
+
+    // ─── Sanity glue: TS-side reference frame parses on Kotlin ──
+
+    @Test
+    fun tsStyleProxyApprovalFrameParsesAndStructurallyMatches() {
+        // Construct a frame the way @shade/sdk would emit it via JSON,
+        // and check our Kotlin types accept the same field names.
+        val expected = ProxyApprovalFrame(
+            requestId = "00112233445566778899aabbccddeeff",
+            decision = "approve",
+            approverFingerprint = "fp",
+            signature = "ab".repeat(64),
+            domain = DEFAULT_APPROVAL_DOMAIN,
+        )
+        assertEquals("linkApproveByProxy", expected.kind)
+        assertEquals("approve", expected.decision)
+
+        val req = ApprovalRequestFrame(
+            requestId = "00112233445566778899aabbccddeeff",
+            hostAddress = "device:h",
+            hostFingerprint = "host-fp",
+            requestingDevice = ApprovalRequestingDevice(
+                fingerprint = "req-fp",
+                receivedAt = 1L,
+            ),
+            expiresAt = 2L,
+            domain = DEFAULT_APPROVAL_DOMAIN,
+        )
+        assertNotNull(req)
+    }
+}