fix(toolintent): exempt list_dir from reference-exists + rejection-loop breaker

Greenfield discovery/analyst stages thrashed on plane-2 REFERENCE_EXISTS
rejections: the model listed a not-yet-created dir (e.g. frontend/), got
hard-BLOCKED every round, and burned MAX_TOOL_ROUNDS without progress.

- New ToolCapability.DIRECTORY_LIST; ListDirTool declares it alongside
  FILE_READ. ReferenceExistsRule now exempts directory enumeration (a
  listing of an absent dir truthfully reports empty; only hallucinated
  file *reads* still fail loud). Dispatch stays on capability, not name.
- Stage-agnostic rejection-loop breaker in the tool loop: after 3 rounds
  where every tool call is rejected (BLOCKED/ERROR) with no success,
  force the model to produce its output. Covers JSON-emitting stages the
  read-loop breaker (file_written-only) never protected.

core/toolintent/src/main/kotlin/com/correx/core/toolintent/rules/ReferenceExistsRule.kt

@@ -17,11 +17,16 @@ import java.nio.file.Path
  * hallucinated a filename fails loud and self-corrects (list the directory, fix the name) instead of
  * proceeding on an empty/absent read. Out-of-workspace targets are [PathContainmentRule]'s concern
  * (it prompts), so this gate stays silent on them to avoid double-handling.
+ *
+ * Directory-enumeration tools ([ToolCapability.DIRECTORY_LIST]) are exempt: listing a not-yet-created
+ * directory is a legitimate survey move (greenfield scaffolding, e.g. "does frontend/ exist yet?")
+ * and the tool itself truthfully reports absent/empty. Hard-blocking it only makes weak models thrash
+ * on a rejection loop, whereas a hallucinated file *read* still fails loud.
  */
 class ReferenceExistsRule : ToolCallRule {
 
     override fun appliesTo(capabilities: Set<ToolCapability>): Boolean =
-        ToolCapability.FILE_READ in capabilities
+        ToolCapability.FILE_READ in capabilities && ToolCapability.DIRECTORY_LIST !in capabilities
 
     override fun assess(input: ToolCallAssessmentInput): ToolCallAssessment {
         val workspaceReal = input.probe.resolveReal(input.workspace.workspaceRoot)

core/toolintent/src/test/kotlin/com/correx/core/toolintent/ReferenceExistsRuleTest.kt

@@ -38,6 +38,13 @@ class ReferenceExistsRuleTest {
         assertFalse(rule.appliesTo(setOf(ToolCapability.FILE_WRITE)))
     }
 
+    @Test
+    fun `directory-enumeration tools are exempt`() {
+        // list_dir carries FILE_READ + DIRECTORY_LIST; listing a not-yet-created dir is a legitimate
+        // survey move, so the anti-hallucination read gate must not block it.
+        assertFalse(rule.appliesTo(setOf(ToolCapability.FILE_READ, ToolCapability.DIRECTORY_LIST)))
+    }
+
     @Test
     fun `reading a non-existent in-workspace path is blocked`() {
         val r = rule.assess(input("/work/project/src/Ghost.kt", FakeProbe(existing = emptySet())))