feat(context): inject CLAUDE.md / AGENTS.md as L0 standing context

On session start, discover CLAUDE.md and AGENTS.md at the bound workspace root and inject
their (concatenated, header-labeled) contents as an L0 system context entry for every stage —
mirroring the .correx/project.toml ProjectProfile path end to end. Recorded as
AgentInstructionsBoundEvent (invariant #9) so replay reads the recorded fact, not the live
file; folded into SessionState.boundAgentInstructions and rendered by buildAgentInstructionsEntry
right after the project profile. AgentInstructionsLoader reads root-only, both files if present.
Bound via ServerModule.bindAgentInstructions alongside bindProjectProfile.

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

core/config/src/main/kotlin/com/correx/core/config/AgentInstructions.kt

@@ -0,0 +1,17 @@
+package com.correx.core.config
+
+import kotlinx.serialization.Serializable
+
+/**
+ * Standing agent instructions discovered at the bound workspace root (`CLAUDE.md` and/or
+ * `AGENTS.md`). Unlike the curated `.correx/project.toml` ProjectProfile, these are the
+ * free-form markdown briefs the operator already maintains for coding agents: injected as
+ * L0 for every stage of every session bound to the workspace.
+ */
+@Serializable
+data class AgentInstructions(
+    val sources: List<String> = emptyList(),
+    val content: String = "",
+) {
+    fun isEmpty(): Boolean = sources.isEmpty() && content.isBlank()
+}

core/config/src/main/kotlin/com/correx/core/config/AgentInstructionsLoader.kt

@@ -0,0 +1,35 @@
+package com.correx.core.config
+
+import java.nio.file.Files
+import java.nio.file.Path
+import java.nio.file.Paths
+
+/**
+ * Discovers standing agent instructions (`CLAUDE.md`, `AGENTS.md`) at the bound workspace
+ * root only — no parent walk, no nested lookup. Mirrors [ProjectProfileLoader]: the loaded
+ * snapshot is bound as an event so replay reads the recorded fact, never the live file.
+ */
+object AgentInstructionsLoader {
+    private val FILE_NAMES = listOf("CLAUDE.md", "AGENTS.md")
+
+    fun load(workspaceRoot: String): AgentInstructions {
+        val sections = mutableListOf<String>()
+        val sources = mutableListOf<String>()
+        for (name in FILE_NAMES) {
+            val contents = readIfPresent(Paths.get(workspaceRoot, name))
+            if (contents == null || contents.isBlank()) continue
+            sources.add(name)
+            sections.add("# $name\n\n${contents.trim()}")
+        }
+        if (sections.isEmpty()) return AgentInstructions()
+        return AgentInstructions(sources = sources, content = sections.joinToString("\n\n"))
+    }
+
+    private fun readIfPresent(path: Path): String? {
+        if (!Files.exists(path)) return null
+        return runCatching { Files.readString(path) }.getOrElse { e ->
+            System.err.println("Warning: Failed to read agent instructions at $path: ${e.message}")
+            null
+        }
+    }
+}

core/config/src/test/kotlin/com/correx/core/config/AgentInstructionsLoaderTest.kt

@@ -0,0 +1,57 @@
+package com.correx.core.config
+
+import org.junit.jupiter.api.Assertions.assertEquals
+import org.junit.jupiter.api.Assertions.assertFalse
+import org.junit.jupiter.api.Assertions.assertTrue
+import org.junit.jupiter.api.Test
+import org.junit.jupiter.api.io.TempDir
+import java.nio.file.Files
+import java.nio.file.Path
+
+class AgentInstructionsLoaderTest {
+
+    @Test
+    fun `both files present yields both sections and sources`(@TempDir root: Path) {
+        Files.writeString(root.resolve("CLAUDE.md"), "Claude rules")
+        Files.writeString(root.resolve("AGENTS.md"), "Agents rules")
+
+        val loaded = AgentInstructionsLoader.load(root.toString())
+
+        assertEquals(listOf("CLAUDE.md", "AGENTS.md"), loaded.sources)
+        assertTrue(loaded.content.contains("# CLAUDE.md"), "content: ${loaded.content}")
+        assertTrue(loaded.content.contains("Claude rules"), "content: ${loaded.content}")
+        assertTrue(loaded.content.contains("# AGENTS.md"), "content: ${loaded.content}")
+        assertTrue(loaded.content.contains("Agents rules"), "content: ${loaded.content}")
+        assertFalse(loaded.isEmpty())
+    }
+
+    @Test
+    fun `only one file present yields that one`(@TempDir root: Path) {
+        Files.writeString(root.resolve("AGENTS.md"), "Agents only")
+
+        val loaded = AgentInstructionsLoader.load(root.toString())
+
+        assertEquals(listOf("AGENTS.md"), loaded.sources)
+        assertTrue(loaded.content.contains("# AGENTS.md"), "content: ${loaded.content}")
+        assertTrue(loaded.content.contains("Agents only"), "content: ${loaded.content}")
+        assertFalse(loaded.content.contains("CLAUDE.md"), "content: ${loaded.content}")
+    }
+
+    @Test
+    fun `neither file present is empty`(@TempDir root: Path) {
+        val loaded = AgentInstructionsLoader.load(root.toString())
+
+        assertTrue(loaded.isEmpty())
+        assertEquals(AgentInstructions(), loaded)
+    }
+
+    @Test
+    fun `blank file is skipped`(@TempDir root: Path) {
+        Files.writeString(root.resolve("CLAUDE.md"), "   \n  ")
+        Files.writeString(root.resolve("AGENTS.md"), "Real content")
+
+        val loaded = AgentInstructionsLoader.load(root.toString())
+
+        assertEquals(listOf("AGENTS.md"), loaded.sources)
+    }
+}