perf(nip77): use kmp-negentropy v1.1.1 PrefixSumStorageVector for O(1) range fingerprints

kmp-negentropy v1.1.1 adds the `IStorage.fingerprint(begin, end)` seam we needed
and ships `PrefixSumStorageVector` — a drop-in IStorage that builds an additive
prefix-sum table on seal() and answers any range fingerprint in O(1) instead of
re-walking the range. Range fingerprints are the CPU-bound core of a NEG-MSG on
a large snapshot; profiling pinned them as the steady-state reconcile cost geode
lost multiples on (not serialization).

Seal a `PrefixSumStorageVector` in both `NegentropyServerSession.sealVector`
(server / relay-relay responder, also backs the `LiveNegentropyIndex` snapshot
cache) and `NegentropySession` (initiator). Byte-identical to the plain vector —
only the fingerprint path is accelerated. `NegentropyPrefixFingerprintTest` now
also asserts the library's `PrefixSumStorageVector.fingerprint` matches the plain
walk over 2000 random ranges + boundaries at 50k; the reconcile-shaped mix
measures 601× (447 ms → 0.7 ms).

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_012EZeWww5TJnzBZKPoc6mvU

gradle/libs.versions.toml

@@ -52,7 +52,7 @@ material3 = "1.9.0"
 media3 = "1.10.1"
 mockk = "1.14.11"
 kotlinx-coroutines-test = "1.11.0"
-negentropyKmp = "v1.0.2"
+negentropyKmp = "v1.1.1"
 netUrlencoderLibVersion = "1.6.0"
 navigationCompose = "2.9.8"
 okhttp = "5.4.0"

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip77Negentropy/NegentropyServerSession.kt

@@ -22,7 +22,7 @@ package com.vitorpamplona.quartz.nip77Negentropy
 
 import com.vitorpamplona.negentropy.Negentropy
 import com.vitorpamplona.negentropy.storage.IStorage
-import com.vitorpamplona.negentropy.storage.StorageVector
+import com.vitorpamplona.negentropy.storage.PrefixSumStorageVector
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.store.IdAndTime
 import com.vitorpamplona.quartz.utils.Hex
@@ -76,9 +76,16 @@ class NegentropyServerSession(
          */
         const val DEFAULT_FRAME_SIZE_LIMIT: Long = 500_000L
 
-        /** Builds and seals a [StorageVector] from `(created_at, id)` pairs. */
-        fun sealVector(localEntries: List<IdAndTime>): StorageVector {
-            val storage = StorageVector()
+        /**
+         * Builds and seals a [PrefixSumStorageVector] from `(created_at, id)`
+         * pairs. The prefix-sum table (built once on [seal]) answers every
+         * range fingerprint the reconcile walk needs in O(1) instead of
+         * O(range), which is the bulk of a NEG-MSG's server-side cost on a
+         * large snapshot. It's a drop-in [IStorage], byte-identical to the
+         * plain vector — only the fingerprint path is accelerated.
+         */
+        fun sealVector(localEntries: List<IdAndTime>): IStorage {
+            val storage = PrefixSumStorageVector()
             for (entry in localEntries) {
                 storage.insert(entry.createdAt, entry.id)
             }

quartz/src/commonMain/kotlin/com/vitorpamplona/quartz/nip77Negentropy/NegentropySync.kt

@@ -21,7 +21,7 @@
 package com.vitorpamplona.quartz.nip77Negentropy
 
 import com.vitorpamplona.negentropy.Negentropy
-import com.vitorpamplona.negentropy.storage.StorageVector
+import com.vitorpamplona.negentropy.storage.PrefixSumStorageVector
 import com.vitorpamplona.quartz.nip01Core.core.Event
 import com.vitorpamplona.quartz.nip01Core.relay.filters.Filter
 import com.vitorpamplona.quartz.nip01Core.store.IdAndTime
@@ -70,7 +70,7 @@ class NegentropySession(
             )
     }
 
-    private val storage = StorageVector()
+    private val storage = PrefixSumStorageVector()
     private val negentropy: Negentropy
 
     init {

quartz/src/jvmTest/kotlin/com/vitorpamplona/quartz/nip01Core/relay/prodbench/NegentropyPrefixFingerprintTest.kt

@@ -21,6 +21,7 @@
 package com.vitorpamplona.quartz.nip01Core.relay.prodbench
 
 import com.vitorpamplona.negentropy.fingerprint.FingerprintCalculator
+import com.vitorpamplona.negentropy.storage.PrefixSumStorageVector
 import com.vitorpamplona.negentropy.storage.StorageVector
 import com.vitorpamplona.quartz.utils.Hex
 import com.vitorpamplona.quartz.utils.sha256.sha256
@@ -153,6 +154,13 @@ class NegentropyPrefixFingerprintTest {
         storage.seal()
         val library = FingerprintCalculator()
 
+        // The library's accelerated storage (now wired into quartz via
+        // `NegentropyServerSession.sealVector`): same entries, prefix-sum
+        // table built on seal. Every range must match the plain walk.
+        val accelerated = PrefixSumStorageVector()
+        ids.forEachIndexed { i, id -> accelerated.insert(1_700_000_000L + i, id) }
+        accelerated.seal()
+
         val index = PrefixFingerprintIndex(ids)
         val rnd = Random(42)
 
@@ -164,10 +172,16 @@ class NegentropyPrefixFingerprintTest {
             val lo = minOf(a, b)
             val hi = maxOf(a, b)
             if (lo == hi) return@repeat
+            val expected = library.run(storage, lo, hi).bytes
             assertContentEquals(
-                library.run(storage, lo, hi).bytes,
+                expected,
                 index.fingerprint(lo, hi),
-                "fingerprint mismatch for [$lo,$hi)",
+                "prototype fingerprint mismatch for [$lo,$hi)",
+            )
+            assertContentEquals(
+                expected,
+                accelerated.fingerprint(lo, hi).bytes,
+                "PrefixSumStorageVector fingerprint mismatch for [$lo,$hi)",
             )
             checked++
         }