feat(cas): content-addressed artifact store (steps 1–8)

New core:artifacts-store interface + infrastructure/artifacts-cas
implementation: segment files + SQLite index, Blake3 hashing,
group-commit fsync via flushBefore, recovery tail-scan, manual
compactor, and oldest-first disk-cap evictor.

Inference events now carry promptArtifactId / responseArtifactId;
orchestrators put bytes before emitting. SqliteEventStore wraps
its txn in artifactStore.flushBefore so segment data is fsynced
before the event commit, making the crash window non-corrupting
(TailScanner re-indexes orphan tail records on reopen).

Compactor and evictor are mutually exclusive via maintenanceMutex.
Step 9 (cloud sync) deferred to a later epic.

See docs/reviews/2026-05-18-cas-steps-1-8-review.md for the final
review.

infrastructure/inference/llama_cpp/src/main/kotlin/com/correx/infrastructure/inference/llama/cpp/DefaultModelManager.kt

@@ -30,12 +30,13 @@ import java.io.File
  * 
  * Thread-safe: all public methods use Mutex for synchronization.
  */
-@Suppress("LongParameterList", "TooGenericExceptionCaught", "UnusedPrivateProperty")
+@Suppress("LongParameterList", "TooGenericExceptionCaught")
 class DefaultModelManager(
     private val llamaServerBin: String = "llama-server",
     private val host: String = "127.0.0.1",
     private val port: Int = 10000,
     private val healthTimeoutMs: Long = 30_000L,
+    @Suppress("UnusedPrivateProperty")
     private val eventStore: EventStore,
     private val httpClient: HttpClient,
     private val eventDispatcher: EventDispatcher,

infrastructure/inference/llama_cpp/src/main/kotlin/com/correx/infrastructure/inference/llama/cpp/LlamaCppInferenceProvider.kt

@@ -15,6 +15,7 @@ import com.correx.infrastructure.inference.commons.ModelDescriptor
 import io.ktor.client.HttpClient
 import io.ktor.client.call.body
 import io.ktor.client.engine.cio.CIO
+import io.ktor.client.plugins.HttpTimeout
 import io.ktor.client.plugins.contentnegotiation.ContentNegotiation
 import io.ktor.client.request.accept
 import io.ktor.client.request.get
@@ -25,6 +26,8 @@ import io.ktor.http.contentType
 import io.ktor.serialization.kotlinx.json.json
 import kotlinx.serialization.json.Json
 
+private const val DEFAULT_REQUEST_TIMEOUT_MS = 60_000L
+
 private fun defaultHttpClient(): HttpClient = HttpClient(CIO) {
     install(ContentNegotiation) {
         json(
@@ -35,6 +38,9 @@ private fun defaultHttpClient(): HttpClient = HttpClient(CIO) {
             },
         )
     }
+    install(HttpTimeout) {
+        requestTimeoutMillis = DEFAULT_REQUEST_TIMEOUT_MS
+    }
 }
 
 @Suppress("TooGenericExceptionCaught", "MagicNumber")