feat(context): purify leading SYSTEM, route context layers as USER turns (#290)

Move intent, repo map, docs catalog, decision journal and relevant-files
context entries to EntryRole.USER so they no longer fold into the single
leading SYSTEM block — that block stays pure policy/schema. Omit L3 repo-map
retrieval on repair retries (the transcript already carries the evidence).
Add "initialIntent" to REQUIRED_SOURCE_TYPES.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

testing/deterministic/src/test/kotlin/PromptRendererOrderingTest.kt

@@ -123,6 +123,29 @@ class PromptRendererOrderingTest {
         )
     }
 
+    @Test
+    fun `USER-role context entries render as separate turns and never fold into system`() {
+        // #290: intent, repo map, docs catalog and decision journal carry EntryRole.USER so the
+        // leading system block stays pure policy/schema. They must appear as user turns, not merge in.
+        val pack = ContextPack(
+            id = ContextPackId("p"),
+            sessionId = sessionId,
+            stageId = stageId,
+            layers = mapOf(
+                ContextLayer.L0 to listOf(entry("policy", ContextLayer.L0, EntryRole.SYSTEM, "systemPrompt")),
+                ContextLayer.L1 to listOf(entry("intent", ContextLayer.L1, EntryRole.USER, "initialIntent")),
+                ContextLayer.L3 to listOf(entry("journal", ContextLayer.L3, EntryRole.USER, "decisionJournal")),
+            ),
+            budgetUsed = 30,
+            budgetLimit = 4000,
+        )
+        val messages = PromptRenderer.render(pack)
+        assertEquals("policy", messages.first().content, "leading system must be policy only")
+        org.junit.jupiter.api.Assertions.assertEquals(1, messages.count { it.role == "system" })
+        org.junit.jupiter.api.Assertions.assertTrue(messages.any { it.role == "user" && it.content == "intent" })
+        org.junit.jupiter.api.Assertions.assertTrue(messages.any { it.role == "user" && it.content == "journal" })
+    }
+
     @Test
     fun `non-L0 SYSTEM entries fold into the single leading system message`() {
         // Strict chat templates (Qwen) 400 on any system message after index 0. Recalled L3

testing/integration/src/test/kotlin/ToolCallGateTest.kt

@@ -110,7 +110,9 @@ class ToolCallGateTest {
 
     /** A tool that declares an output compressor (strips blank lines) — the Tier-A seam under test. */
     private inner class FakeCompressingTool(override val tier: Tier = Tier.T1) : Tool {
-        override val name = "file_write"
+        // Non-write tool: #289 elides successful write receipts before FORMAT_COMPRESS, so this
+        // must be a generic tool to actually exercise the outputCompressor (blank-line stripping).
+        override val name = "shell_run"
         override val description = "fake compressing tool"
         override val parametersSchema: JsonObject = buildJsonObject {}
         override val requiredCapabilities: Set<ToolCapability> = setOf(ToolCapability.FILE_WRITE)
@@ -374,7 +376,7 @@ class ToolCallGateTest {
         val (orchestrator, _, provider) = buildOrchestrator(executor, FakeCompressingTool(), assessorRule = null)
         val config = OrchestrationConfig(retryPolicy = RetryPolicy(maxAttempts = 1, backoffMs = 0))
 
-        orchestrator.run(SessionId("compress"), singleStageGraph(), config)
+        orchestrator.run(SessionId("compress"), singleStageGraph(setOf("shell_run")), config)
 
         // The second inference carries round-1's tool result in its context pack — compressed
         // (blank lines stripped), not raw, under the uniform `[tool exit=N]` frame the model sees.
@@ -382,7 +384,7 @@ class ToolCallGateTest {
         // only shapes the derived context entry.
         val secondPack = provider.requests[1].contextPack
         val toolEntry = secondPack.layers.values.flatten().first { it.sourceType == "toolResult" }
-        assertEquals("[file_write exit=0]\nline1\nline2\nline3", toolEntry.content)
+        assertEquals("[shell_run exit=0]\nline1\nline2\nline3", toolEntry.content)
     }
 
     @Test

testing/kernel/src/test/kotlin/ContextFeedbackTest.kt

@@ -233,14 +233,14 @@ class ContextFeedbackTest {
     }
 
     @Test
-    fun `buildRelevantFilesEntry produces L3 system entry with Relevant files header`() {
+    fun `buildRelevantFilesEntry produces L3 user entry with Relevant files header`() {
         val hits = listOf(
             RepoKnowledgeHit(path = "src/Parser.kt", text = "src/Parser.kt: Parser, Lexer", score = 0.9f),
             RepoKnowledgeHit(path = "src/Main.kt", text = "src/Main.kt: main", score = 0.7f),
         )
         val entry = buildRelevantFilesEntry(hits)
         assertEquals(ContextLayer.L3, entry.layer)
-        assertEquals(EntryRole.SYSTEM, entry.role)
+        assertEquals(EntryRole.USER, entry.role)
         assertEquals("relevantFiles", entry.sourceType)
         assertTrue(entry.content.startsWith("## Relevant files"), "content: ${entry.content}")
         assertTrue(entry.content.contains("src/Parser.kt"), "content: ${entry.content}")