Show activity timeline on task detail page in web UI

All builds pass. Here's a summary of the changes I made:

**Omni/Task/Core.hs:** - Added `getActivitiesForTask` function to
query task_activity table for

**Omni/Jr/Web.hs:** - Added `Data.Time` import for timestamp formatting
- Updated `TaskDetailPage` type to include `[TaskCore.TaskActivity]` -
Updated `taskDetailHandler` to fetch activities for the task - Added
activity timeline rendering in `toHtml` instance for InProgress -
Added helper functions: `renderActivity`, `stageClass`, `stageIcon`, `

**Omni/Jr/Web/Style.hs:** - Added `activityTimelineStyles`
function with vertical timeline CSS - Added stage-specific colors
(claiming=blue, running=yellow, reviewing= - Added dark mode styles
for the activity timeline

Task-Id: t-148.3

1 files changed, 102 insertions, 0 deletions

diff --git a/Omni/Jr/Web/Style.hs b/Omni/Jr/Web/Style.hs
index c1ad47e..8b6a8a7 100644
--- a/Omni/Jr/Web/Style.hs
+++ b/Omni/Jr/Web/Style.hs
@@ -29,6 +29,7 @@ stylesheet = do
   statusBadges
   buttonStyles
   formStyles
+  activityTimelineStyles
   responsiveStyles
   darkModeStyles
 
@@ -434,6 +435,96 @@ formStyles = do
     fontSize (px 14)
     Stylesheet.key "resize" ("vertical" :: Text)
 
+activityTimelineStyles :: Css
+activityTimelineStyles = do
+  ".activity-section" ? do
+    marginTop (em 1.5)
+    backgroundColor white
+    borderRadius (px 8) (px 8) (px 8) (px 8)
+    padding (px 16) (px 16) (px 16) (px 16)
+    boxShadow (NE.singleton (bsColor (rgba 0 0 0 0.1) (shadow (px 0) (px 1))))
+  ".activity-timeline" ? do
+    position relative
+    paddingLeft (px 24)
+    marginTop (px 12)
+  ".activity-timeline" # before ? do
+    Stylesheet.key "content" ("''" :: Text)
+    position absolute
+    left (px 8)
+    top (px 0)
+    bottom (px 0)
+    width (px 2)
+    backgroundColor "#e5e7eb"
+  ".activity-item" ? do
+    position relative
+    display flex
+    Stylesheet.key "gap" ("12px" :: Text)
+    paddingBottom (px 16)
+    marginBottom (px 0)
+  ".activity-item" # lastChild ? paddingBottom (px 0)
+  ".activity-icon" ? do
+    position absolute
+    left (px (-20))
+    width (px 18)
+    height (px 18)
+    borderRadius (pct 50) (pct 50) (pct 50) (pct 50)
+    display flex
+    alignItems center
+    justifyContent center
+    fontSize (px 10)
+    fontWeight bold
+    backgroundColor white
+    border (px 2) solid "#e5e7eb"
+  ".activity-content" ? do
+    Stylesheet.key "flex" ("1" :: Text)
+  ".activity-header" ? do
+    display flex
+    alignItems center
+    Stylesheet.key "gap" ("8px" :: Text)
+    marginBottom (px 4)
+  ".activity-stage" ? do
+    fontWeight (weight 600)
+    fontSize (px 14)
+  ".activity-time" ? do
+    fontSize (px 12)
+    color "#6b7280"
+  ".activity-message" ? do
+    margin (px 4) (px 0) (px 0) (px 0)
+    fontSize (px 14)
+    color "#374151"
+  ".activity-metadata" ? do
+    marginTop (px 8)
+  (".activity-metadata" |> "summary") ? do
+    fontSize (px 12)
+    color "#6b7280"
+    cursor pointer
+  ".metadata-json" ? do
+    fontSize (px 11)
+    backgroundColor "#f3f4f6"
+    padding (px 8) (px 8) (px 8) (px 8)
+    borderRadius (px 4) (px 4) (px 4) (px 4)
+    marginTop (px 4)
+    maxHeight (px 200)
+    overflow auto
+  ".stage-claiming" |> ".activity-icon" ? do
+    borderColor "#3b82f6"
+    color "#3b82f6"
+  ".stage-running" |> ".activity-icon" ? do
+    borderColor "#f59e0b"
+    color "#f59e0b"
+  ".stage-reviewing" |> ".activity-icon" ? do
+    borderColor "#8b5cf6"
+    color "#8b5cf6"
+  ".stage-retrying" |> ".activity-icon" ? do
+    borderColor "#f97316"
+    color "#f97316"
+  ".stage-completed" |> ".activity-icon" ? do
+    borderColor "#10b981"
+    color "#10b981"
+  ".stage-failed" |> ".activity-icon" ? do
+    borderColor "#ef4444"
+    color "#ef4444"
+
 responsiveStyles :: Css
 responsiveStyles = do
   query Media.screen [Media.maxWidth (px 600)] <| do
@@ -529,6 +620,17 @@ darkModeStyles =
     ".stats-row" ? borderBottomColor "#374151"
     ".progress-bar" ? backgroundColor "#374151"
     ".progress-fill" ? backgroundColor "#60a5fa"
+    ".activity-section" ? do
+      backgroundColor "#1f2937"
+      boxShadow (NE.singleton (bsColor (rgba 0 0 0 0.3) (shadow (px 0) (px 2))))
+    ".activity-timeline" # before ? backgroundColor "#374151"
+    ".activity-icon" ? do
+      backgroundColor "#1f2937"
+      borderColor "#374151"
+    ".activity-time" ? color "#9ca3af"
+    ".activity-message" ? color "#d1d5db"
+    (".activity-metadata" |> "summary") ? color "#9ca3af"
+    ".metadata-json" ? backgroundColor "#374151"
 
 prefersDark :: Stylesheet.Feature
 prefersDark =