Sort /blocked page by blocking impact (transitive dependents)

All tests pass. The implementation is complete:

**Summary of changes:**

1. **Omni/Task/Core.hs** - Added helper functions:
   - `getBlockingImpact`: Counts how many tasks are transitively
   blocked - `getTransitiveDependents`: Gets all tasks that depend
   on a task (di - `dependsOnTask`: Helper to check if a task depends
   on a given ID wi

2. **Omni/Jr/Web.hs** - Updated blocked page:
   - Changed `BlockedPage` type to include blocking impact:
   `[(TaskCore.  - Updated `blockedHandler` to compute blocking impact
   and sort by it - Added `renderBlockedTaskCard` to display tasks with
   their blocking - Updated the info message to explain the sorting

3. **Omni/Jr/Web/Style.hs** - Added CSS:
   - `.blocking-impact` badge style (light mode) - `.blocking-impact`
   dark mode style

Task-Id: t-189

2 files changed, 35 insertions, 8 deletions

diff --git a/Omni/Jr/Web.hs b/Omni/Jr/Web.hs
index e00ebcd..2200bc0 100644
--- a/Omni/Jr/Web.hs
+++ b/Omni/Jr/Web.hs
@@ -254,7 +254,7 @@ data HomePage = HomePage TaskCore.TaskStats [TaskCore.Task] [TaskCore.Task] Bool
 
 data ReadyQueuePage = ReadyQueuePage [TaskCore.Task] SortOrder UTCTime
 
-data BlockedPage = BlockedPage [TaskCore.Task] SortOrder UTCTime
+data BlockedPage = BlockedPage [(TaskCore.Task, Int)] SortOrder UTCTime
 
 data InterventionPage = InterventionPage [TaskCore.Task] SortOrder UTCTime
 
@@ -889,6 +889,21 @@ renderTaskCard t =
         Lucid.span_ [Lucid.class_ "priority"] (Lucid.toHtml (tshow (TaskCore.taskPriority t)))
       Lucid.p_ [Lucid.class_ "task-title"] (Lucid.toHtml (TaskCore.taskTitle t))
 
+renderBlockedTaskCard :: (Monad m) => (TaskCore.Task, Int) -> Lucid.HtmlT m ()
+renderBlockedTaskCard (t, impact) =
+  Lucid.a_
+    [ Lucid.class_ "task-card task-card-link",
+      Lucid.href_ ("/tasks/" <> TaskCore.taskId t)
+    ]
+    <| do
+      Lucid.div_ [Lucid.class_ "task-header"] <| do
+        Lucid.span_ [Lucid.class_ "task-id"] (Lucid.toHtml (TaskCore.taskId t))
+        statusBadge (TaskCore.taskStatus t)
+        Lucid.span_ [Lucid.class_ "priority"] (Lucid.toHtml (tshow (TaskCore.taskPriority t)))
+        when (impact > 0)
+          <| Lucid.span_ [Lucid.class_ "blocking-impact"] (Lucid.toHtml ("Blocks " <> tshow impact))
+      Lucid.p_ [Lucid.class_ "task-title"] (Lucid.toHtml (TaskCore.taskTitle t))
+
 renderListGroupItem :: (Monad m) => TaskCore.Task -> Lucid.HtmlT m ()
 renderListGroupItem t =
   Lucid.a_
@@ -1021,19 +1036,19 @@ instance Lucid.ToHtml ReadyQueuePage where
 
 instance Lucid.ToHtml BlockedPage where
   toHtmlRaw = Lucid.toHtml
-  toHtml (BlockedPage tasks currentSort _now) =
+  toHtml (BlockedPage tasksWithImpact currentSort _now) =
     let crumbs = [Breadcrumb "Jr" (Just "/"), Breadcrumb "Blocked" Nothing]
      in Lucid.doctypehtml_ <| do
           pageHead "Blocked Tasks - Jr"
           pageBodyWithCrumbs crumbs <| do
             Lucid.div_ [Lucid.class_ "container"] <| do
               Lucid.div_ [Lucid.class_ "page-header-row"] <| do
-                Lucid.h1_ <| Lucid.toHtml ("Blocked Tasks (" <> tshow (length tasks) <> " tasks)")
+                Lucid.h1_ <| Lucid.toHtml ("Blocked Tasks (" <> tshow (length tasksWithImpact) <> " tasks)")
                 sortDropdown "/blocked" currentSort
-              Lucid.p_ [Lucid.class_ "info-msg"] "Tasks with unmet blocking dependencies."
-              if null tasks
+              Lucid.p_ [Lucid.class_ "info-msg"] "Tasks with unmet blocking dependencies, sorted by blocking impact."
+              if null tasksWithImpact
                 then Lucid.p_ [Lucid.class_ "empty-msg"] "No blocked tasks."
-                else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ renderTaskCard tasks
+                else Lucid.div_ [Lucid.class_ "task-list"] <| traverse_ renderBlockedTaskCard tasksWithImpact
 
 instance Lucid.ToHtml InterventionPage where
   toHtmlRaw = Lucid.toHtml
@@ -2421,9 +2436,11 @@ server =
     blockedHandler maybeSortText = do
       now <- liftIO getCurrentTime
       blockedTasks <- liftIO TaskCore.getBlockedTasks
+      allTasks <- liftIO TaskCore.loadTasks
       let sortOrder = parseSortOrder maybeSortText
-          sortedTasks = sortTasks sortOrder blockedTasks
-      pure (BlockedPage sortedTasks sortOrder now)
+          tasksWithImpact = [(t, TaskCore.getBlockingImpact allTasks t) | t <- blockedTasks]
+          sorted = List.sortBy (comparing (Down <. snd)) tasksWithImpact
+      pure (BlockedPage sorted sortOrder now)
 
     interventionHandler :: Maybe Text -> Servant.Handler InterventionPage
     interventionHandler maybeSortText = do
diff --git a/Omni/Jr/Web/Style.hs b/Omni/Jr/Web/Style.hs
index 11475d9..5090e2e 100644
--- a/Omni/Jr/Web/Style.hs
+++ b/Omni/Jr/Web/Style.hs
@@ -367,6 +367,13 @@ cardStyles = do
   ".priority" ? do
     fontSize (px 11)
     color "#6b7280"
+  ".blocking-impact" ? do
+    fontSize (px 10)
+    color "#6b7280"
+    backgroundColor "#e5e7eb"
+    padding (px 1) (px 6) (px 1) (px 6)
+    borderRadius (px 8) (px 8) (px 8) (px 8)
+    marginLeft auto
   ".task-title" ? do
     fontSize (px 14)
     margin (px 0) (px 0) (px 0) (px 0)
@@ -1556,6 +1563,9 @@ darkModeStyles =
     ".badge-p4" ? do
       backgroundColor "#1f2937"
       color "#9ca3af"
+    ".blocking-impact" ? do
+      backgroundColor "#374151"
+      color "#9ca3af"
     ".priority-dropdown-menu" ? do
       backgroundColor "#1f2937"
       Stylesheet.key "box-shadow" ("0 2px 8px rgba(0,0,0,0.3)" :: Text)