fix: PAUSED resume after server restart, diff viewer only shows last tool

apps/server/src/main/kotlin/com/correx/apps/server/ServerModule.kt

@@ -9,7 +9,9 @@ import com.correx.core.approvals.DefaultApprovalRepository
 import com.correx.core.artifactstore.ArtifactStore
 import com.correx.core.config.ApprovalConfig
 import com.correx.core.events.events.ApprovalRequestedEvent
+import com.correx.core.events.events.OrchestrationResumedEvent
 import com.correx.core.events.stores.EventStore
+import com.correx.core.events.types.SessionId
 import com.correx.core.kernel.orchestration.DefaultSessionOrchestrator
 import com.correx.core.kernel.orchestration.OrchestrationConfig
 import com.correx.core.kernel.orchestration.OrchestrationRepository
@@ -17,6 +19,7 @@ import com.correx.core.router.RouterFacade
 import com.correx.core.sessions.DefaultSessionRepository
 import com.correx.core.tools.registry.ToolRegistry
 import com.correx.core.events.orchestration.OrchestrationStatus
+import java.util.concurrent.ConcurrentHashMap
 import kotlinx.coroutines.CoroutineScope
 import kotlinx.coroutines.Dispatchers
 import kotlinx.coroutines.Job
@@ -55,6 +58,7 @@ class ServerModule(
     )
 
     private var subscriptionJob: Job? = null
+    private val activeSessionJobs = ConcurrentHashMap<SessionId, Job>()
 
     /**
      * Subscribe to the event store and forward [ApprovalRequestedEvent] payloads to
@@ -73,26 +77,50 @@ class ServerModule(
             .filter { it.payload is ApprovalRequestedEvent }
             .onEach { approvalCoordinator.onApprovalRequested(it.payload as ApprovalRequestedEvent) }
             .launchIn(moduleScope)
+
+        // When a PAUSED session's approval is resolved without a live orchestrator coroutine
+        // (server was restarted while approval was pending), emit OrchestrationResumedEvent
+        // triggers this subscription to continue the session.
+        eventStore.subscribeAll()
+            .filter { it.payload is OrchestrationResumedEvent }
+            .onEach { event ->
+                val sessionId = (event.payload as OrchestrationResumedEvent).sessionId
+                if (activeSessionJobs.containsKey(sessionId)) return@onEach
+                val orchState = orchestrationRepository.getState(sessionId)
+                if (orchState.status != OrchestrationStatus.RUNNING) return@onEach
+                val graph = workflowRegistry.find(orchState.workflowId) ?: return@onEach
+                launchSessionResume(sessionId, graph)
+            }
+            .launchIn(moduleScope)
+    }
+
+    private fun launchSessionResume(sessionId: SessionId, graph: com.correx.core.transitions.graph.WorkflowGraph) {
+        if (activeSessionJobs.containsKey(sessionId)) return
+        val job = moduleScope.launch {
+            runCatching {
+                orchestrator.resume(sessionId, graph, defaultOrchestrationConfig)
+            }.onFailure { e ->
+                log.error("resumeSession: session={} failed", sessionId.value, e)
+            }
+            activeSessionJobs.remove(sessionId)
+        }
+        activeSessionJobs[sessionId] = job
     }
 
     private fun resumeAbandonedSessions() {
         eventStore.allSessionIds().forEach { sessionId ->
             val orchState = orchestrationRepository.getState(sessionId)
-            if (orchState.status != OrchestrationStatus.RUNNING &&
-                orchState.status != OrchestrationStatus.PAUSED
-            ) return@forEach
+            // Skip PAUSED sessions — they are waiting for user approval, not for computation.
+            // preRegisterPendingApprovals() already routes their responses. When the user
+            // approves, submitApprovalDecision emits OrchestrationResumedEvent which triggers
+            // the subscription above to continue the session.
+            if (orchState.status != OrchestrationStatus.RUNNING) return@forEach
             val graph = workflowRegistry.find(orchState.workflowId) ?: run {
                 log.warn("resumeAbandoned: no graph for session={} workflowId={}", sessionId.value, orchState.workflowId)
                 return@forEach
             }
             log.info("resumeAbandoned: launching session={} workflow={}", sessionId.value, orchState.workflowId)
-            moduleScope.launch {
-                runCatching {
-                    orchestrator.resume(sessionId, graph, defaultOrchestrationConfig)
-                }.onFailure { e ->
-                    log.error("resumeAbandoned: session={} failed", sessionId.value, e)
-                }
-            }
+            launchSessionResume(sessionId, graph)
         }
     }
 

apps/tui/src/main/kotlin/com/correx/apps/tui/TuiApp.kt

@@ -163,9 +163,9 @@ private fun renderIdleLayout(frame: Frame, state: TuiState) {
 private fun renderInSessionLayout(frame: Frame, state: TuiState) {
     val area = frame.area()
     val selectedSession = state.sessions.sessions.firstOrNull { it.id == state.sessions.selectedId }
-    val hasDiff = selectedSession?.tools?.any {
-        it.status == ToolDisplayStatus.COMPLETED && it.diff != null
-    } == true
+    val hasDiff = selectedSession?.tools
+        ?.lastOrNull { it.status == ToolDisplayStatus.COMPLETED }
+        ?.diff != null
 
     val constraints = mutableListOf(
         Constraint.length(STATUS_HEIGHT),
@@ -197,12 +197,20 @@ private fun renderInSessionLayout(frame: Frame, state: TuiState) {
 
 private fun renderApprovalLayout(frame: Frame, state: TuiState) {
     val area = frame.area()
+    val selectedSession = state.sessions.sessions.firstOrNull { it.id == state.sessions.selectedId }
+    val hasDiff = selectedSession?.tools
+        ?.lastOrNull { it.status == ToolDisplayStatus.COMPLETED }
+        ?.diff != null
+
     val constraints = mutableListOf(
         Constraint.length(STATUS_HEIGHT),
     )
     if (state.eventStripVisible) {
         constraints.add(Constraint.length(EVENT_STRIP_HEIGHT))
     }
+    if (hasDiff) {
+        constraints.add(Constraint.length(DIFF_HEIGHT))
+    }
     constraints.add(Constraint.fill())
     constraints.add(Constraint.length(INPUT_HEIGHT))
 
@@ -215,6 +223,9 @@ private fun renderApprovalLayout(frame: Frame, state: TuiState) {
     if (state.eventStripVisible) {
         frame.renderWidget(eventHistoryStripWidget(state), vertRects[rectIdx++])
     }
+    if (hasDiff) {
+        frame.renderWidget(diffViewerWidget(state), vertRects[rectIdx++])
+    }
     frame.renderWidget(approvalSurfaceWidget(state), vertRects[rectIdx++])
     frame.renderWidget(inputBarWidget(state, DisplayState.APPROVAL), vertRects[rectIdx])
 }

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

@@ -23,8 +23,11 @@ private val yellowStyle = Style.create().yellow()
 fun diffViewerWidget(state: TuiState): Paragraph {
     val selectedSession = state.sessions.sessions.firstOrNull { it.id == state.sessions.selectedId }
 
+    // Only show the diff for the most recently completed tool. If the last tool has no diff
+    // (e.g. a shell command), the viewer is hidden — stale diffs from earlier tools are noise.
     val toolWithDiff = selectedSession?.tools
-        ?.lastOrNull { it.status == ToolDisplayStatus.COMPLETED && it.diff != null }
+        ?.lastOrNull { it.status == ToolDisplayStatus.COMPLETED }
+        ?.takeIf { it.diff != null }
 
     val diffText = toolWithDiff?.diff ?: return Paragraph.builder().build()