feat: convert router panel to conversation output log with user messages

Replace raw string routerMessages with structured RouterEntry(role, content)
entries. User messages are stored locally on SubmitInput (both IDLE and
IN_SESSION). Router responses arrive as 'router' entries via
RouterResponseMessage. Tool diffs arrive as 'tool' entries.

RouterPanel renders as a styled conversation log with role prefixes:
  ▸ user msgs in accent, router replies in strong body, tool output in dim.
Multi-line content (diffs, long responses) is split on \n for proper display.
Panel title changed from 'router' to 'output' to reflect the log role.

apps/tui/src/main/kotlin/com/correx/apps/tui/components/RouterPanel.kt

@@ -1,5 +1,6 @@
 package com.correx.apps.tui.components
 
+import com.correx.apps.tui.state.RouterEntry
 import com.correx.apps.tui.state.TuiState
 import dev.tamboui.text.Line
 import dev.tamboui.text.Span
@@ -12,17 +13,33 @@ import dev.tamboui.widgets.paragraph.Paragraph
 fun routerPanelWidget(state: TuiState): Paragraph {
     val lines = buildList<Line> {
         if (!state.routerConnected) {
-            add(Line.from(Span.styled("not connected — epic 14", Theme.dimStyle)))
+            add(Line.from(Span.styled("awaiting router response...", Theme.dimStyle)))
         } else {
             val msgs = state.routerMessages[state.sessions.selectedId].orEmpty()
-            for (msg in msgs) {
+            for (entry in msgs) {
-                add(Line.from(Span.raw(msg)))
+                val style = when (entry.role) {
+                    "user" -> Theme.accentStyle
+                    "router" -> Theme.fgStrongStyle
+                    "tool" -> Theme.dimStyle
+                    else -> Theme.fgStrongStyle
+                }
+                val prefix = when (entry.role) {
+                    "user" -> "\u25b8 "
+                    "router" -> "  "
+                    "tool" -> "  "
+                    else -> ""
+                }
+                val contentLines = entry.content.split("\n")
+                contentLines.forEachIndexed { i, lineContent ->
+                    val text = if (i == 0) "$prefix$lineContent" else "  $lineContent"
+                    add(Line.from(Span.styled(text, style)))
+                }
             }
         }
     }
 
     val block = Block.builder()
-        .title("router")
+        .title("output")
         .borders(Borders.ALL)
         .borderType(BorderType.ROUNDED)
         .build()

apps/tui/src/main/kotlin/com/correx/apps/tui/reducer/RootReducer.kt

@@ -6,6 +6,7 @@ import com.correx.apps.tui.input.Action
 import com.correx.apps.tui.state.DisplayState
 import com.correx.apps.tui.state.InputMode
 import com.correx.apps.tui.state.ProviderType
+import com.correx.apps.tui.state.RouterEntry
 import com.correx.apps.tui.state.TuiState
 import com.correx.apps.tui.state.displayState
 import org.slf4j.LoggerFactory
@@ -139,13 +140,23 @@ object RootReducer {
                         val updatedHistory = (currentHistory + text).takeLast(50)
                         withBgReset.copy(
                             inputHistory = withBgReset.inputHistory + (selectedId to updatedHistory),
+                            routerMessages = withBgReset.routerMessages.run {
+                                this + (selectedId to (this[selectedId].orEmpty() + RouterEntry("user", text)))
+                            },
                         )
                     }
 
                     // Optimistic session created by SessionsReducer for IDLE chat submit.
                     sessions.selectedId != null && prevInputMode == InputMode.ROUTER &&
-                        withBgReset.displayState == DisplayState.IDLE ->
+                        withBgReset.displayState == DisplayState.IDLE -> {
-                        withBgReset.copy(sessionEntered = true)
+                        val selectedId = sessions.selectedId!!
+                        withBgReset.copy(
+                            sessionEntered = true,
+                            routerMessages = withBgReset.routerMessages.run {
+                                this + (selectedId to (this[selectedId].orEmpty() + RouterEntry("user", text)))
+                            },
+                        )
+                    }
 
                     else -> withBgReset
                 }
@@ -175,7 +186,7 @@ object RootReducer {
                             routerConnected = true,
                             routerMessages = withBgReset.routerMessages.run {
                                 val key = msg.sessionId.value
-                                this + (key to (this[key].orEmpty() + msg.content))
+                                this + (key to (this[key].orEmpty() + RouterEntry("router", msg.content)))
                             },
                         )
                     }
@@ -183,7 +194,7 @@ object RootReducer {
                         withBgReset.copy(
                             routerMessages = withBgReset.routerMessages.run {
                                 val key = msg.sessionId.value
-                                this + (key to (this[key].orEmpty() + msg.diff!!))
+                                this + (key to (this[key].orEmpty() + RouterEntry("tool", msg.diff!!)))
                             },
                         )
                     }

apps/tui/src/main/kotlin/com/correx/apps/tui/state/TuiState.kt

@@ -23,6 +23,16 @@ data class TuiEventEntry(
     val detail: String,
 )
 
+/**
+ * A single entry in the router conversation log.
+ * @property role one of "user", "router", or "tool"
+ * @property content the message text
+ */
+data class RouterEntry(
+    val role: String,
+    val content: String,
+)
+
 data class TuiState(
     val connection: ConnectionState = ConnectionState(),
     val sessions: SessionsState = SessionsState(),
@@ -46,7 +56,7 @@ data class TuiState(
     val currentModel: String? = null,
     val providerType: ProviderType = ProviderType.LOCAL,
     val routerConnected: Boolean = false,
-    val routerMessages: Map<String, List<String>> = emptyMap(),
+    val routerMessages: Map<String, List<RouterEntry>> = emptyMap(),
     val diffExpanded: Boolean = false,
     val diffScrollOffset: Int = 0,
     val chatMode: ChatMode = ChatMode.CHAT,

apps/tui/src/test/kotlin/com/correx/apps/tui/reducer/RootReducerTest.kt

@@ -9,6 +9,7 @@ import com.correx.apps.tui.state.ConnectionState
 import com.correx.apps.tui.state.DisplayState
 import com.correx.apps.tui.state.InputMode
 import com.correx.apps.tui.state.ProviderType
+import com.correx.apps.tui.state.RouterEntry
 import com.correx.apps.tui.state.SessionSummary
 import com.correx.apps.tui.state.SessionsState
 import com.correx.apps.tui.state.TuiState
@@ -391,27 +392,31 @@ class RootReducerTest {
     }
 
     @Test
-    fun `ToolCompleted with diff appends diff content to per-session routerMessages`() {
+    fun `ToolCompleted with diff appends diff as tool entry to per-session routerMessages`() {
         val initial = TuiState(snapshotPhase = false)
+        val diff = "--- a/file.txt\n+++ b/file.txt\n@@ -1 +1 @@\n-old content\n+new content"
         val toolCompleted = ServerMessage.ToolCompleted(
             sessionId = SessionId("s1"),
             toolName = "file_write",
             outputSummary = "wrote 3 lines",
             occurredAt = fixedClock(),
-            diff = "--- a/file.txt\n+++ b/file.txt\n@@ -1 +1 @@\n-old content\n+new content",
+            diff = diff,
             sequence = 1L,
             sessionSequence = 1L,
         )
         val (state, _) = RootReducer.reduce(initial, Action.ServerEventReceived(toolCompleted), fixedClock)
         val msgs = state.routerMessages["s1"]
         assertEquals(1, msgs?.size)
-        assertTrue(msgs?.first()?.contains("--- a/file.txt") == true)
+        val entry = msgs?.first()
-        assertTrue(msgs?.first()?.contains("+new content") == true)
+        assertEquals("tool", entry?.role)
+        assertTrue(entry?.content?.contains("--- a/file.txt") == true)
+        assertTrue(entry?.content?.contains("+new content") == true)
     }
 
     @Test
     fun `ToolCompleted without diff does not append to routerMessages`() {
-        val initial = TuiState(snapshotPhase = false, routerMessages = mapOf("s1" to listOf("existing msg")))
+        val existing = listOf(RouterEntry("user", "existing msg"))
+        val initial = TuiState(snapshotPhase = false, routerMessages = mapOf("s1" to existing))
         val toolCompleted = ServerMessage.ToolCompleted(
             sessionId = SessionId("s1"),
             toolName = "file_write",
@@ -424,7 +429,7 @@ class RootReducerTest {
         val (state, _) = RootReducer.reduce(initial, Action.ServerEventReceived(toolCompleted), fixedClock)
         val msgs = state.routerMessages["s1"]
         assertEquals(1, msgs?.size)
-        assertEquals("existing msg", msgs?.first())
+        assertEquals(RouterEntry("user", "existing msg"), msgs?.first())
     }
 
     @Test
@@ -440,8 +445,8 @@ class RootReducerTest {
         )
         val after1 = RootReducer.reduce(initial, Action.ServerEventReceived(msg1), fixedClock).first
         val after2 = RootReducer.reduce(after1, Action.ServerEventReceived(msg2), fixedClock).first
-        assertEquals(listOf("hello from s1"), after2.routerMessages["s1"])
+        assertEquals(listOf(RouterEntry("router", "hello from s1")), after2.routerMessages["s1"])
-        assertEquals(listOf("hello from s2"), after2.routerMessages["s2"])
+        assertEquals(listOf(RouterEntry("router", "hello from s2")), after2.routerMessages["s2"])
     }
 
     @Test