feat: render display_kind timeline markers as chips, not user bubbles (#904) (#909)

Co-authored-by: M57 <hy4ri@users.noreply.github.com>

app/src/test/java/com/m57/hermescontrol/ui/chat/FullBleedTurnsTest.kt

@@ -81,6 +81,45 @@ class FullBleedTurnsTest {
         assertEquals(listOf(entries(AgentEntry.SystemEvent(s))), result)
     }
 
+    @Test
+    fun `display_kind marker is a SystemEvent entry not a user turn`() {
+        val marker =
+            msg("m1", MessageRole.USER, content = "[System: The active model has changed to gpt-5]")
+                .copy(displayKind = "model_switch")
+        val result = groupIntoTurns(listOf(marker))
+        assertEquals(listOf<ChatTurn>(entries(AgentEntry.SystemEvent(marker))), result)
+    }
+
+    @Test
+    fun `marker between assistant and user does not close the agent turn`() {
+        val a = msg("a1", MessageRole.ASSISTANT)
+        val marker =
+            msg("m1", MessageRole.USER, content = "marker")
+                .copy(displayKind = "personality_switch")
+        val u = msg("u1", MessageRole.USER)
+        val result = groupIntoTurns(listOf(a, marker, u))
+        assertEquals(
+            listOf(
+                entries(AgentEntry.Prose(a), AgentEntry.SystemEvent(marker)),
+                ChatTurn.User(u),
+            ),
+            result,
+        )
+    }
+
+    @Test
+    fun `marker only closes nothing and trailing marker lands in agent turn`() {
+        val u = msg("u1", MessageRole.USER)
+        val marker =
+            msg("m1", MessageRole.USER, content = "marker")
+                .copy(displayKind = "auto_continue")
+        val result = groupIntoTurns(listOf(u, marker))
+        assertEquals(
+            listOf(ChatTurn.User(u), entries(AgentEntry.SystemEvent(marker))),
+            result,
+        )
+    }
+
     @Test
     fun `user message closes the current agent turn`() {
         val a1 = msg("a1", MessageRole.ASSISTANT)

app/src/test/java/com/m57/hermescontrol/ui/chat/fullbleed/TimelineMarkerTest.kt

@@ -0,0 +1,59 @@
+package com.m57.hermescontrol.ui.chat.fullbleed
+
+import com.m57.hermescontrol.R
+import org.junit.Assert.assertEquals
+import org.junit.Assert.assertNull
+import org.junit.Test
+
+class TimelineMarkerTest {
+    @Test
+    fun knownKindsMapToLabels() {
+        assertEquals(R.string.timeline_marker_model_switch, timelineMarkerLabelRes("model_switch"))
+        assertEquals(
+            R.string.timeline_marker_personality_switch,
+            timelineMarkerLabelRes("personality_switch"),
+        )
+        assertEquals(R.string.timeline_marker_auto_continue, timelineMarkerLabelRes("auto_continue"))
+        assertEquals(
+            R.string.timeline_marker_delegation_complete,
+            timelineMarkerLabelRes("async_delegation_complete"),
+        )
+    }
+
+    @Test
+    fun unknownAndNullKindsHaveNoLabel() {
+        assertNull(timelineMarkerLabelRes("hidden"))
+        assertNull(timelineMarkerLabelRes("some_future_kind"))
+        assertNull(timelineMarkerLabelRes(null))
+        assertNull(timelineMarkerLabelRes(""))
+    }
+
+    @Test
+    fun modelParsedFromMarkerContent() {
+        assertEquals(
+            "gpt-5",
+            markerModelFromContent(
+                "[System: The active model for this chat has changed to gpt-5 via provider openai. ...]",
+            ),
+        )
+        assertEquals(
+            "deepseek-v4",
+            markerModelFromContent(
+                "The active model for this chat has changed to deepseek-v4. From this point forward...",
+            ),
+        )
+        assertEquals(
+            "gpt-4.5",
+            markerModelFromContent(
+                "The active model for this chat has changed to gpt-4.5 via provider openai.",
+            ),
+        )
+    }
+
+    @Test
+    fun modelParseHandlesMissingOrOddContent() {
+        assertNull(markerModelFromContent(""))
+        assertNull(markerModelFromContent("[System: personality switched]"))
+        assertNull(markerModelFromContent("changed to"))
+    }
+}