Add time range filter to homepage Task Status section

The build and tests pass with no errors. The time range filter
feature f

**Implementation summary:** - Route accepts
`?range=today|week|month|all` query param - `TimeRange` type with
`Today`, `Week`, `Month`, `AllTime` variants - `homeHandler` filters
both tasks and activities by time range - Toggle buttons rendered
with `timeFilterBtn` helper - Full CSS styling in `timeFilterStyles`
with dark mode support - Default selection: "All Time"

Task-Id: t-180

2 files changed, 160 insertions, 12 deletions

diff --git a/Omni/Jr/Web.hs b/Omni/Jr/Web.hs
index 533d761..3380b93 100644
--- a/Omni/Jr/Web.hs
+++ b/Omni/Jr/Web.hs
@@ -21,7 +21,8 @@ import qualified Data.List as List
 import qualified Data.Text as Text
 import qualified Data.Text.Lazy as LazyText
 import qualified Data.Text.Lazy.Encoding as LazyText
-import Data.Time (NominalDiffTime, UTCTime, defaultTimeLocale, diffUTCTime, formatTime, getCurrentTime)
+import Data.Time (Day, NominalDiffTime, UTCTime (..), dayOfWeek, defaultTimeLocale, diffUTCTime, formatTime, getCurrentTime, toGregorian)
+import Data.Time.Calendar (DayOfWeek (..))
 import Data.Time.Clock.POSIX (posixSecondsToUTCTime, utcTimeToPOSIXSeconds)
 import qualified Lucid
 import qualified Lucid.Base as Lucid
@@ -89,8 +90,85 @@ data TaskFilters = TaskFilters
   }
   deriving (Show, Eq)
 
+data TimeRange = Today | Week | Month | AllTime
+  deriving (Show, Eq)
+
+parseTimeRange :: Maybe Text -> TimeRange
+parseTimeRange (Just "today") = Today
+parseTimeRange (Just "week") = Week
+parseTimeRange (Just "month") = Month
+parseTimeRange _ = AllTime
+
+timeRangeToParam :: TimeRange -> Text
+timeRangeToParam Today = "today"
+timeRangeToParam Week = "week"
+timeRangeToParam Month = "month"
+timeRangeToParam AllTime = "all"
+
+getTimeRangeStart :: TimeRange -> UTCTime -> Maybe UTCTime
+getTimeRangeStart AllTime _ = Nothing
+getTimeRangeStart Today now = Just (startOfDay now)
+getTimeRangeStart Week now = Just (startOfWeek now)
+getTimeRangeStart Month now = Just (startOfMonth now)
+
+startOfDay :: UTCTime -> UTCTime
+startOfDay t = UTCTime (utctDay t) 0
+
+startOfWeek :: UTCTime -> UTCTime
+startOfWeek t =
+  let day = utctDay t
+      dow = dayOfWeek day
+      daysBack = case dow of
+        Monday -> 0
+        Tuesday -> 1
+        Wednesday -> 2
+        Thursday -> 3
+        Friday -> 4
+        Saturday -> 5
+        Sunday -> 6
+   in UTCTime (addDays (negate daysBack) day) 0
+
+addDays :: Integer -> Day -> Day
+addDays n d =
+  let (y, m, dayNum) = toGregorian d
+   in fromGregorian y m (dayNum + fromInteger n)
+
+fromGregorian :: Integer -> Int -> Int -> Day
+fromGregorian y m d = toEnum (fromInteger (daysSinceEpoch y m d))
+
+daysSinceEpoch :: Integer -> Int -> Int -> Integer
+daysSinceEpoch y m d =
+  let a = (14 - m) `div` 12
+      y' = y + 4800 - toInteger a
+      m' = m + 12 * a - 3
+      jdn = d + (153 * m' + 2) `div` 5 + 365 * fromInteger y' + fromInteger y' `div` 4 - fromInteger y' `div` 100 + fromInteger y' `div` 400 - 32045
+   in toInteger jdn - 2440588
+
+startOfMonth :: UTCTime -> UTCTime
+startOfMonth t =
+  let day = utctDay t
+      (y, m, _) = toGregorian day
+   in UTCTime (fromGregorian y m 1) 0
+
+computeMetricsFromActivities :: [TaskCore.Task] -> [TaskCore.TaskActivity] -> TaskCore.AggregatedMetrics
+computeMetricsFromActivities tasks activities =
+  let completedCount = length [t | t <- tasks, TaskCore.taskStatus t == TaskCore.Done]
+      totalCost = sum [c | act <- activities, Just c <- [TaskCore.activityCostCents act]]
+      totalTokens = sum [t | act <- activities, Just t <- [TaskCore.activityTokensUsed act]]
+      totalDuration = sum [calcDuration act | act <- activities]
+   in TaskCore.AggregatedMetrics
+        { TaskCore.aggTotalCostCents = totalCost,
+          TaskCore.aggTotalDurationSeconds = totalDuration,
+          TaskCore.aggCompletedTasks = completedCount,
+          TaskCore.aggTotalTokens = totalTokens
+        }
+  where
+    calcDuration act = case (TaskCore.activityStartedAt act, TaskCore.activityCompletedAt act) of
+      (Just start, Just end) -> floor (diffUTCTime end start)
+      _ -> 0
+
 type API =
-  Get '[Lucid.HTML] HomePage
+  QueryParam "range" Text :> Get '[Lucid.HTML] HomePage
     :<|> "style.css" :> Get '[CSS] LazyText.Text
     :<|> "ready" :> Get '[Lucid.HTML] ReadyQueuePage
     :<|> "blocked" :> Get '[Lucid.HTML] BlockedPage
@@ -139,7 +217,7 @@ instance Accept CSS where
 instance MimeRender CSS LazyText.Text where
   mimeRender _ = LazyText.encodeUtf8
 
-data HomePage = HomePage TaskCore.TaskStats [TaskCore.Task] [TaskCore.Task] Bool TaskCore.AggregatedMetrics UTCTime
+data HomePage = HomePage TaskCore.TaskStats [TaskCore.Task] [TaskCore.Task] Bool TaskCore.AggregatedMetrics TimeRange UTCTime
 
 data ReadyQueuePage = ReadyQueuePage [TaskCore.Task] UTCTime
 
@@ -611,12 +689,17 @@ renderListGroupItem t =
 
 instance Lucid.ToHtml HomePage where
   toHtmlRaw = Lucid.toHtml
-  toHtml (HomePage stats readyTasks recentTasks hasMoreRecent globalMetrics _now) =
+  toHtml (HomePage stats readyTasks recentTasks hasMoreRecent globalMetrics currentRange _now) =
     Lucid.doctypehtml_ <| do
       pageHead "Jr Dashboard"
       pageBody <| do
         Lucid.div_ [Lucid.class_ "container"] <| do
           Lucid.h2_ "Task Status"
+          Lucid.div_ [Lucid.class_ "time-filter"] <| do
+            timeFilterBtn "Today" Today currentRange
+            timeFilterBtn "This Week" Week currentRange
+            timeFilterBtn "This Month" Month currentRange
+            timeFilterBtn "All Time" AllTime currentRange
           Lucid.div_ [Lucid.class_ "stats-grid"] <| do
             statCard "Open" (TaskCore.openTasks stats) "badge-open" "/tasks?status=Open"
             statCard "In Progress" (TaskCore.inProgressTasks stats) "badge-inprogress" "/tasks?status=InProgress"
@@ -695,6 +778,16 @@ instance Lucid.ToHtml HomePage where
                 mins = (totalSeconds `mod` 3600) `div` 60
              in tshow hours <> "h " <> tshow mins <> "m"
 
+      timeFilterBtn :: (Monad m) => Text -> TimeRange -> TimeRange -> Lucid.HtmlT m ()
+      timeFilterBtn label range current =
+        let activeClass = if range == current then " active" else ""
+            href = "/?" <> "range=" <> timeRangeToParam range
+         in Lucid.a_
+              [ Lucid.href_ href,
+                Lucid.class_ ("time-filter-btn" <> activeClass)
+              ]
+              (Lucid.toHtml label)
+
 instance Lucid.ToHtml ReadyQueuePage where
   toHtmlRaw = Lucid.toHtml
   toHtml (ReadyQueuePage tasks _now) =
@@ -2036,17 +2129,26 @@ server =
     styleHandler :: Servant.Handler LazyText.Text
     styleHandler = pure Style.css
 
-    homeHandler :: Servant.Handler HomePage
-    homeHandler = do
+    homeHandler :: Maybe Text -> Servant.Handler HomePage
+    homeHandler maybeRangeText = do
       now <- liftIO getCurrentTime
-      stats <- liftIO <| TaskCore.getTaskStats Nothing
-      readyTasks <- liftIO TaskCore.getReadyTasks
+      let range = parseTimeRange maybeRangeText
+          maybeStart = getTimeRangeStart range now
       allTasks <- liftIO TaskCore.loadTasks
-      globalMetrics <- liftIO TaskCore.getGlobalAggregatedMetrics
-      let sortedTasks = List.sortBy (flip compare `on` TaskCore.taskUpdatedAt) allTasks
+      let filteredTasks = case maybeStart of
+            Nothing -> allTasks
+            Just start -> [t | t <- allTasks, TaskCore.taskUpdatedAt t >= start]
+          stats = TaskCore.computeTaskStatsFromList filteredTasks
+      readyTasks <- liftIO TaskCore.getReadyTasks
+      allActivities <- liftIO <| concat </ traverse (TaskCore.getActivitiesForTask <. TaskCore.taskId) allTasks
+      let filteredActivities = case maybeStart of
+            Nothing -> allActivities
+            Just start -> [a | a <- allActivities, TaskCore.activityTimestamp a >= start]
+          globalMetrics = computeMetricsFromActivities filteredTasks filteredActivities
+          sortedTasks = List.sortBy (flip compare `on` TaskCore.taskUpdatedAt) filteredTasks
           recentTasks = take 5 sortedTasks
-          hasMoreRecent = length allTasks > 5
-      pure (HomePage stats readyTasks recentTasks hasMoreRecent globalMetrics now)
+          hasMoreRecent = length filteredTasks > 5
+      pure (HomePage stats readyTasks recentTasks hasMoreRecent globalMetrics range now)
 
     readyQueueHandler :: Servant.Handler ReadyQueuePage
     readyQueueHandler = do
diff --git a/Omni/Jr/Web/Style.hs b/Omni/Jr/Web/Style.hs
index ad1ff02..e0cc51e 100644
--- a/Omni/Jr/Web/Style.hs
+++ b/Omni/Jr/Web/Style.hs
@@ -36,6 +36,7 @@ stylesheet = do
   markdownStyles
   retryBannerStyles
   taskMetaStyles
+  timeFilterStyles
   responsiveStyles
   darkModeStyles
 
@@ -1185,6 +1186,37 @@ retryBannerStyles = do
     color "#991b1b"
     fontWeight (weight 500)
 
+timeFilterStyles :: Css
+timeFilterStyles = do
+  ".time-filter" ? do
+    display flex
+    Stylesheet.key "gap" ("6px" :: Text)
+    marginBottom (px 12)
+    flexWrap Flexbox.wrap
+  ".time-filter-btn" ? do
+    display inlineBlock
+    padding (px 4) (px 12) (px 4) (px 12)
+    fontSize (px 12)
+    fontWeight (weight 500)
+    textDecoration none
+    borderRadius (px 12) (px 12) (px 12) (px 12)
+    border (px 1) solid "#d0d0d0"
+    backgroundColor white
+    color "#374151"
+    transition "all" (ms 150) ease (sec 0)
+    cursor pointer
+  ".time-filter-btn" # hover ? do
+    borderColor "#999"
+    backgroundColor "#f3f4f6"
+    textDecoration none
+  ".time-filter-btn.active" ? do
+    backgroundColor "#0066cc"
+    borderColor "#0066cc"
+    color white
+  ".time-filter-btn.active" # hover ? do
+    backgroundColor "#0055aa"
+    borderColor "#0055aa"
+
 taskMetaStyles :: Css
 taskMetaStyles = do
   ".task-meta" ? do
@@ -1443,6 +1475,20 @@ darkModeStyles =
     ".fact-create-form" ? do
       backgroundColor "#1f2937"
       borderColor "#374151"
+    ".time-filter-btn" ? do
+      backgroundColor "#374151"
+      borderColor "#4b5563"
+      color "#d1d5db"
+    ".time-filter-btn" # hover ? do
+      backgroundColor "#4b5563"
+      borderColor "#6b7280"
+    ".time-filter-btn.active" ? do
+      backgroundColor "#3b82f6"
+      borderColor "#3b82f6"
+      color white
+    ".time-filter-btn.active" # hover ? do
+      backgroundColor "#2563eb"
+      borderColor "#2563eb"
     -- Responsive dark mode: dropdown content needs background on mobile
     query Media.screen [Media.maxWidth (px 600)] <| do
       ".navbar-dropdown-content" ? do