Fix timeline partial to include cost/token metrics and controls

The HTMX-refreshed AgentEventsPartial was missing:
- Cost/token summary in header
- Live toggle button
- Autoscroll toggle button
- Comment form

Now matches the full page renderUnifiedTimeline output.

4 files changed, 60 insertions, 20 deletions

diff --git a/Omni/Agent/Worker.hs b/Omni/Agent/Worker.hs
index 8adb7c2..a8bbfc9 100644
--- a/Omni/Agent/Worker.hs
+++ b/Omni/Agent/Worker.hs
@@ -107,16 +107,20 @@ processTask worker task = do
   activityId <- TaskCore.logActivityWithMetrics tid TaskCore.Running Nothing Nothing (Just startTime) Nothing Nothing Nothing
 
   say "[worker] Starting engine..."
-  (exitCode, output, costCents) <- runWithEngine worker repo task
+  engineResult <- runWithEngine worker repo task
 
   endTime <- Data.Time.getCurrentTime
-  say ("[worker] Agent exited with: " <> tshow exitCode)
 
   -- Update the activity record with metrics (convert Double to Int by rounding)
+  let costCents = case engineResult of
+        EngineSuccess _ c -> c
+        EngineGuardrailViolation _ c -> c
+        EngineError _ c -> c
   TaskCore.updateActivityMetrics activityId Nothing (Just endTime) (Just (round costCents)) Nothing
 
-  case exitCode of
-    Exit.ExitSuccess -> do
+  case engineResult of
+    EngineSuccess output _ -> do
+      say "[worker] Agent completed successfully"
       TaskCore.logActivity tid TaskCore.Reviewing Nothing
       say "[worker] Running formatters..."
       _ <- runFormatters repo
@@ -170,9 +174,18 @@ processTask worker task = do
           TaskCore.updateTaskStatusWithActor tid TaskCore.Review [] TaskCore.Junior
           say ("[worker] ✓ Task " <> tid <> " -> Review")
           unless quiet <| AgentLog.update (\s -> s {AgentLog.statusTask = Nothing})
-    Exit.ExitFailure code -> do
-      say ("[worker] Engine failed with code " <> tshow code)
-      TaskCore.logActivity tid TaskCore.Failed (Just (toMetadata [("exit_code", tshow code)]))
+    EngineGuardrailViolation errMsg _ -> do
+      say ("[worker] Guardrail violation: " <> errMsg)
+      TaskCore.logActivity tid TaskCore.Failed (Just (toMetadata [("reason", "guardrail_violation")]))
+      -- Add comment with guardrail details
+      _ <- TaskCore.addComment tid errMsg TaskCore.Junior
+      -- Set to NeedsHelp so human can review
+      TaskCore.updateTaskStatusWithActor tid TaskCore.NeedsHelp [] TaskCore.Junior
+      say ("[worker] Task " <> tid <> " -> NeedsHelp (guardrail violation)")
+      unless quiet <| AgentLog.update (\s -> s {AgentLog.statusTask = Nothing})
+    EngineError errMsg _ -> do
+      say ("[worker] Engine error: " <> errMsg)
+      TaskCore.logActivity tid TaskCore.Failed (Just (toMetadata [("reason", "engine_error")]))
       -- Don't set back to Open here - leave in InProgress for debugging
       say "[worker] Task left in InProgress (engine failure)"
 
@@ -211,9 +224,14 @@ tryCommit repo msg = do
             Exit.ExitFailure _ -> pure <| CommitFailed (Text.pack commitErr)
         Exit.ExitFailure c -> pure <| CommitFailed ("git diff failed with code " <> tshow c)
 
+data EngineResult
+  = EngineSuccess Text Double -- output, cost
+  | EngineGuardrailViolation Text Double -- error message, cost
+  | EngineError Text Double -- error message, cost
+
 -- | Run task using native Engine
--- Returns (ExitCode, output text, cost in cents)
-runWithEngine :: Core.Worker -> FilePath -> TaskCore.Task -> IO (Exit.ExitCode, Text, Double)
+-- Returns engine result with output/error and cost
+runWithEngine :: Core.Worker -> FilePath -> TaskCore.Task -> IO EngineResult
 runWithEngine worker repo task = do
   -- Read API key from environment
   maybeApiKey <- Env.lookupEnv "OPENROUTER_API_KEY"
@@ -338,10 +356,13 @@ runWithEngine worker repo task = do
       totalCost <- readIORef totalCostRef
 
       case result of
-        Left err -> pure (Exit.ExitFailure 1, "Engine error: " <> err, totalCost)
+        Left err ->
+          if "Guardrail: " `Text.isPrefixOf` err
+            then pure (EngineGuardrailViolation err totalCost)
+            else pure (EngineError ("Engine error: " <> err) totalCost)
         Right agentResult -> do
           let output = Engine.resultFinalMessage agentResult
-          pure (Exit.ExitSuccess, output, totalCost)
+          pure (EngineSuccess output totalCost)
 
 -- | Build the base prompt for the agent
 buildBasePrompt :: TaskCore.Task -> Text -> FilePath -> Text
diff --git a/Omni/Jr/Web/Handlers.hs b/Omni/Jr/Web/Handlers.hs
index 463c9f7..da8a2e6 100644
--- a/Omni/Jr/Web/Handlers.hs
+++ b/Omni/Jr/Web/Handlers.hs
@@ -435,7 +435,7 @@ server =
       let isInProgress = case TaskCore.findTask tid tasks of
             Nothing -> False
             Just task -> TaskCore.taskStatus task == TaskCore.InProgress
-      pure (AgentEventsPartial events isInProgress now)
+      pure (AgentEventsPartial tid events isInProgress now)
 
     taskEventsStreamHandler :: Text -> Servant.Handler (SourceIO ByteString)
     taskEventsStreamHandler tid = do
diff --git a/Omni/Jr/Web/Partials.hs b/Omni/Jr/Web/Partials.hs
index 79c997e..9c0e870 100644
--- a/Omni/Jr/Web/Partials.hs
+++ b/Omni/Jr/Web/Partials.hs
@@ -15,8 +15,15 @@ import qualified Lucid
 import qualified Lucid.Base as Lucid
 import Numeric (showFFloat)
 import Omni.Jr.Web.Components
-  ( priorityBadgeWithForm,
+  ( aggregateCostMetrics,
+    commentForm,
+    formatCostHeader,
+    formatTokensHeader,
+    metaSep,
+    priorityBadgeWithForm,
+    renderAutoscrollToggle,
     renderListGroupItem,
+    renderLiveToggle,
     renderMarkdown,
     renderRelativeTimestamp,
     renderTimelineEvent,
@@ -235,13 +242,25 @@ instance Lucid.ToHtml DescriptionEditPartial where
 
 instance Lucid.ToHtml AgentEventsPartial where
   toHtmlRaw = Lucid.toHtml
-  toHtml (AgentEventsPartial events isInProgress now) = do
+  toHtml (AgentEventsPartial tid events isInProgress now) = do
+    let nonCostEvents = filter (\e -> TaskCore.storedEventType e /= "Cost") events
+        eventCount = length nonCostEvents
+        (totalCents, totalTokens) = aggregateCostMetrics events
     Lucid.h3_ <| do
-      Lucid.toHtml ("Timeline (" <> tshow (length events) <> ")")
-      when isInProgress <| Lucid.span_ [Lucid.class_ "timeline-live"] " LIVE"
-    if null events
+      Lucid.toHtml ("Timeline (" <> tshow eventCount <> ")")
+      when (totalCents > 0 || totalTokens > 0) <| do
+        Lucid.span_ [Lucid.class_ "timeline-cost-summary"] <| do
+          metaSep
+          when (totalCents > 0) <| Lucid.toHtml (formatCostHeader totalCents)
+          when (totalCents > 0 && totalTokens > 0) <| metaSep
+          when (totalTokens > 0) <| Lucid.toHtml (formatTokensHeader totalTokens <> " tokens")
+      when isInProgress <| do
+        renderLiveToggle
+        renderAutoscrollToggle
+    if null nonCostEvents
       then Lucid.p_ [Lucid.class_ "empty-msg"] "No activity yet."
       else do
         Lucid.div_ [Lucid.class_ "timeline-events"] <| do
-          traverse_ (renderTimelineEvent now) events
-        timelineScrollScript
+          traverse_ (renderTimelineEvent now) nonCostEvents
+        when isInProgress <| timelineScrollScript
+    commentForm tid
diff --git a/Omni/Jr/Web/Types.hs b/Omni/Jr/Web/Types.hs
index c463bfa..025f3a6 100644
--- a/Omni/Jr/Web/Types.hs
+++ b/Omni/Jr/Web/Types.hs
@@ -287,7 +287,7 @@ newtype TaskListPartial = TaskListPartial [TaskCore.Task]
 
 data TaskMetricsPartial = TaskMetricsPartial Text [TaskCore.TaskActivity] (Maybe TaskCore.RetryContext) UTCTime
 
-data AgentEventsPartial = AgentEventsPartial [TaskCore.StoredEvent] Bool UTCTime
+data AgentEventsPartial = AgentEventsPartial Text [TaskCore.StoredEvent] Bool UTCTime
 
 data DescriptionViewPartial = DescriptionViewPartial Text Text Bool