Show git commits for task on detail page

All tests pass. The implementation is complete:

1. Added `GitCommit` data type with hash, short hash, summary,
author, r 2. Added `getCommitsForTask` function that queries `git
log --grep='Task 3. Updated `TaskDetailPage` to include commits
4. Updated `taskDetailHandler` to fetch commits for the task 5. Added
`renderCommit` helper to display each commit with links to `/ta
6. Added CSS styles for the commit list in both light and dark modes

Task-Id: t-153.1

2 files changed, 136 insertions, 3 deletions

diff --git a/Omni/Jr/Web.hs b/Omni/Jr/Web.hs
index 5fc8126..55ff06b 100644
--- a/Omni/Jr/Web.hs
+++ b/Omni/Jr/Web.hs
@@ -93,9 +93,19 @@ newtype InterventionPage = InterventionPage [TaskCore.Task]
 data TaskListPage = TaskListPage [TaskCore.Task] TaskFilters
 
 data TaskDetailPage
-  = TaskDetailFound TaskCore.Task [TaskCore.Task] [TaskCore.TaskActivity] (Maybe TaskCore.RetryContext)
+  = TaskDetailFound TaskCore.Task [TaskCore.Task] [TaskCore.TaskActivity] (Maybe TaskCore.RetryContext) [GitCommit]
   | TaskDetailNotFound Text
 
+data GitCommit = GitCommit
+  { commitHash :: Text,
+    commitShortHash :: Text,
+    commitSummary :: Text,
+    commitAuthor :: Text,
+    commitRelativeDate :: Text,
+    commitFilesChanged :: Int
+  }
+  deriving (Show, Eq)
+
 data TaskReviewPage
   = ReviewPageFound TaskCore.Task ReviewInfo
   | ReviewPageNotFound Text
@@ -406,7 +416,7 @@ instance Lucid.ToHtml TaskDetailPage where
             "The task "
             Lucid.code_ (Lucid.toHtml tid)
             " could not be found."
-  toHtml (TaskDetailFound task allTasks activities maybeRetry) =
+  toHtml (TaskDetailFound task allTasks activities maybeRetry commits) =
     Lucid.doctypehtml_ <| do
       pageHead (TaskCore.taskId task <> " - Jr")
       Lucid.body_ <| do
@@ -496,6 +506,12 @@ instance Lucid.ToHtml TaskDetailPage where
                 Lucid.ul_ [Lucid.class_ "child-list"] <| do
                   traverse_ renderChild children
 
+            unless (null commits) <| do
+              Lucid.div_ [Lucid.class_ "detail-section"] <| do
+                Lucid.h3_ "Git Commits"
+                Lucid.div_ [Lucid.class_ "commit-list"] <| do
+                  traverse_ (renderCommit (TaskCore.taskId task)) commits
+
           let hasRunningActivity = any (\a -> TaskCore.activityStage a == TaskCore.Running) activities
           when hasRunningActivity <| do
             let isInProgress = TaskCore.taskStatus task == TaskCore.InProgress
@@ -546,6 +562,21 @@ instance Lucid.ToHtml TaskDetailPage where
           Lucid.span_ [Lucid.class_ "child-title"] <| Lucid.toHtml (" - " <> TaskCore.taskTitle child)
           Lucid.span_ [Lucid.class_ "child-status"] <| Lucid.toHtml (" [" <> tshow (TaskCore.taskStatus child) <> "]")
 
+      renderCommit :: (Monad m) => Text -> GitCommit -> Lucid.HtmlT m ()
+      renderCommit tid c =
+        Lucid.div_ [Lucid.class_ "commit-item"] <| do
+          Lucid.div_ [Lucid.class_ "commit-header"] <| do
+            Lucid.a_
+              [ Lucid.href_ ("/tasks/" <> tid <> "/diff/" <> commitHash c),
+                Lucid.class_ "commit-hash"
+              ]
+              (Lucid.toHtml (commitShortHash c))
+            Lucid.span_ [Lucid.class_ "commit-summary"] (Lucid.toHtml (commitSummary c))
+          Lucid.div_ [Lucid.class_ "commit-meta"] <| do
+            Lucid.span_ [Lucid.class_ "commit-author"] (Lucid.toHtml (commitAuthor c))
+            Lucid.span_ [Lucid.class_ "commit-date"] (Lucid.toHtml (commitRelativeDate c))
+            Lucid.span_ [Lucid.class_ "commit-files"] (Lucid.toHtml (tshow (commitFilesChanged c) <> " files"))
+
       renderActivity :: (Monad m) => TaskCore.TaskActivity -> Lucid.HtmlT m ()
       renderActivity act =
         Lucid.div_ [Lucid.class_ ("activity-item " <> stageClass (TaskCore.activityStage act))] <| do
@@ -1136,7 +1167,8 @@ server =
         Just task -> do
           activities <- liftIO (TaskCore.getActivitiesForTask tid)
           retryCtx <- liftIO (TaskCore.getRetryContext tid)
-          pure (TaskDetailFound task tasks activities retryCtx)
+          commits <- liftIO (getCommitsForTask tid)
+          pure (TaskDetailFound task tasks activities retryCtx commits)
 
     taskStatusHandler :: Text -> StatusForm -> Servant.Handler StatusBadgePartial
     taskStatusHandler tid (StatusForm newStatus) = do
@@ -1241,6 +1273,59 @@ findCommitForTask tid = do
       (x : _) -> pure (Just (Text.pack x))
       [] -> pure Nothing
 
+getCommitsForTask :: Text -> IO [GitCommit]
+getCommitsForTask tid = do
+  let grepArg = "--grep=Task-Id: " <> Text.unpack tid
+  (code, out, _) <-
+    Process.readProcessWithExitCode
+      "git"
+      ["log", "--pretty=format:%H|%h|%s|%an|%ar", grepArg]
+      ""
+  if code /= Exit.ExitSuccess || null out
+    then pure []
+    else do
+      let commitLines = filter (not <. null) (List.lines out)
+      traverse parseCommitLine commitLines
+  where
+    parseCommitLine :: String -> IO GitCommit
+    parseCommitLine line =
+      case Text.splitOn "|" (Text.pack line) of
+        [sha, shortSha, summary, author, relDate] -> do
+          filesCount <- getFilesChangedCount (Text.unpack sha)
+          pure
+            GitCommit
+              { commitHash = sha,
+                commitShortHash = shortSha,
+                commitSummary = summary,
+                commitAuthor = author,
+                commitRelativeDate = relDate,
+                commitFilesChanged = filesCount
+              }
+        _ ->
+          pure
+            GitCommit
+              { commitHash = Text.pack line,
+                commitShortHash = Text.take 7 (Text.pack line),
+                commitSummary = "(parse error)",
+                commitAuthor = "",
+                commitRelativeDate = "",
+                commitFilesChanged = 0
+              }
+
+    getFilesChangedCount :: String -> IO Int
+    getFilesChangedCount sha = do
+      (code', out', _) <-
+        Process.readProcessWithExitCode
+          "git"
+          ["show", "--stat", "--format=", sha]
+          ""
+      pure
+        <| if code' /= Exit.ExitSuccess
+          then 0
+          else
+            let statLines = filter (not <. null) (List.lines out')
+             in max 0 (length statLines - 1)
+
 checkMergeConflict :: String -> IO (Maybe [Text])
 checkMergeConflict commitSha = do
   (_, origHead, _) <- Process.readProcessWithExitCode "git" ["rev-parse", "HEAD"] ""
diff --git a/Omni/Jr/Web/Style.hs b/Omni/Jr/Web/Style.hs
index b4f4c76..19fc371 100644
--- a/Omni/Jr/Web/Style.hs
+++ b/Omni/Jr/Web/Style.hs
@@ -30,6 +30,7 @@ stylesheet = do
   formStyles
   executionDetailsStyles
   activityTimelineStyles
+  commitStyles
   markdownStyles
   responsiveStyles
   darkModeStyles
@@ -621,6 +622,45 @@ activityTimelineStyles = do
     borderColor "#ef4444"
     color "#ef4444"
 
+commitStyles :: Css
+commitStyles = do
+  ".commit-list" ? do
+    display flex
+    flexDirection column
+    Stylesheet.key "gap" ("4px" :: Text)
+    marginTop (px 8)
+  ".commit-item" ? do
+    padding (px 6) (px 8) (px 6) (px 8)
+    backgroundColor "#f9fafb"
+    borderRadius (px 2) (px 2) (px 2) (px 2)
+    border (px 1) solid "#e5e7eb"
+  ".commit-header" ? do
+    display flex
+    alignItems center
+    Stylesheet.key "gap" ("8px" :: Text)
+    marginBottom (px 2)
+  ".commit-hash" ? do
+    fontFamily ["SF Mono", "Monaco", "monospace"] [monospace]
+    fontSize (px 12)
+    color "#0066cc"
+    textDecoration none
+    backgroundColor "#e5e7eb"
+    padding (px 1) (px 4) (px 1) (px 4)
+    borderRadius (px 2) (px 2) (px 2) (px 2)
+  ".commit-hash" # hover ? textDecoration underline
+  ".commit-summary" ? do
+    fontSize (px 13)
+    color "#374151"
+    fontWeight (weight 500)
+  ".commit-meta" ? do
+    display flex
+    Stylesheet.key "gap" ("12px" :: Text)
+    fontSize (px 11)
+    color "#6b7280"
+  ".commit-author" ? fontWeight (weight 500)
+  ".commit-files" ? do
+    color "#9ca3af"
+
 markdownStyles :: Css
 markdownStyles = do
   ".markdown-content" ? do
@@ -793,6 +833,14 @@ darkModeStyles =
     ".metric-value" ? color "#d1d5db"
     ".amp-link" ? color "#60a5fa"
     ".markdown-content" ? color "#d1d5db"
+    ".commit-item" ? do
+      backgroundColor "#374151"
+      borderColor "#4b5563"
+    ".commit-hash" ? do
+      backgroundColor "#4b5563"
+      color "#60a5fa"
+    ".commit-summary" ? color "#d1d5db"
+    ".commit-meta" ? color "#9ca3af"
     ".md-h1" ? borderBottomColor "#374151"
     ".md-inline-code" ? do
       backgroundColor "#374151"