Add enhanced filtering to task list command

Implement --status and --namespace filters for task list:

New filters: - --status: Filter by open, in-progress, or done -
--namespace: Filter by namespace (e.g., Omni/Task)

All filters can be combined: - task list --parent=t-abc123
--status=open - task list --type=epic --status=done - task list
--namespace="Omni/Task" --status=open

Updated listTasks signature to accept all filter parameters and apply
them in sequence. Updated AGENTS.md with examples.

Closes task t-PpZGVf

2 files changed, 25 insertions, 7 deletions

diff --git a/Omni/Task.hs b/Omni/Task.hs
index f10ae25..ae854a7 100644
--- a/Omni/Task.hs
+++ b/Omni/Task.hs
@@ -35,7 +35,7 @@ task
 Usage:
   task init
   task create <title> [--type=<type>] [--parent=<id>] [--deps=<ids>] [--dep-type=<type>] [--discovered-from=<id>] [--namespace=<ns>]
-  task list [--type=<type>] [--parent=<id>]
+  task list [--type=<type>] [--parent=<id>] [--status=<status>] [--namespace=<ns>]
   task ready
   task update <id> <status>
   task deps <id>
@@ -59,6 +59,7 @@ Options:
   -h --help                     Show this help
   --type=<type>                 Task type: epic or task (default: task)
   --parent=<id>                 Parent epic ID
+  --status=<status>             Filter by status: open, in-progress, done
   --deps=<ids>                  Comma-separated list of dependency IDs
   --dep-type=<type>             Dependency type: blocks, discovered-from, parent-child, related (default: blocks)
   --discovered-from=<id>        Shortcut for --deps=<id> --dep-type=discovered-from
@@ -124,7 +125,19 @@ move args
       maybeParent <- case Cli.getArg args (Cli.longOption "parent") of
         Nothing -> pure Nothing
         Just p -> pure <| Just (T.pack p)
-      tasks <- listTasks maybeType maybeParent
+      maybeStatus <- case Cli.getArg args (Cli.longOption "status") of
+        Nothing -> pure Nothing
+        Just "open" -> pure <| Just Open
+        Just "in-progress" -> pure <| Just InProgress
+        Just "done" -> pure <| Just Done
+        Just other -> panic <| "Invalid status: " <> T.pack other <> ". Use: open, in-progress, or done"
+      maybeNamespace <- case Cli.getArg args (Cli.longOption "namespace") of
+        Nothing -> pure Nothing
+        Just ns -> do
+          let validNs = Namespace.fromHaskellModule ns
+              nsPath = T.pack <| Namespace.toPath validNs
+          pure <| Just nsPath
+      tasks <- listTasks maybeType maybeParent maybeStatus maybeNamespace
       traverse_ printTask tasks
   | args `Cli.has` Cli.command "ready" = do
       tasks <- getReadyTasks
@@ -184,7 +197,7 @@ unitTests =
         null (taskDependencies task) Test.@?= True,
       Test.unit "can list tasks" <| do
         _ <- createTask "Test task for list" WorkTask Nothing Nothing []
-        tasks <- listTasks Nothing Nothing
+        tasks <- listTasks Nothing Nothing Nothing Nothing
         not (null tasks) Test.@?= True,
       Test.unit "ready tasks exclude blocked ones" <| do
         task1 <- createTask "First task" WorkTask Nothing Nothing []
diff --git a/Omni/Task/Core.hs b/Omni/Task/Core.hs
index 6285ef7..140d7dc 100644
--- a/Omni/Task/Core.hs
+++ b/Omni/Task/Core.hs
@@ -5,7 +5,6 @@
 module Omni.Task.Core where
 
 import Alpha
-import Control.Monad ((>>=))
 import Data.Aeson (FromJSON, ToJSON, decode, encode)
 import qualified Data.Aeson as Aeson
 import qualified Data.Aeson.KeyMap as KM
@@ -210,20 +209,26 @@ updateTaskStatus tid newStatus = do
   TIO.writeFile tasksFile ""
   traverse_ saveTask updatedTasks
 
--- List tasks, optionally filtered by type or parent
-listTasks :: Maybe TaskType -> Maybe Text -> IO [Task]
-listTasks maybeType maybeParent = do
+-- List tasks, optionally filtered by type, parent, status, or namespace
+listTasks :: Maybe TaskType -> Maybe Text -> Maybe Status -> Maybe Text -> IO [Task]
+listTasks maybeType maybeParent maybeStatus maybeNamespace = do
   tasks <- loadTasks
   let filtered =
         tasks
           |> filterByType maybeType
           |> filterByParent maybeParent
+          |> filterByStatus maybeStatus
+          |> filterByNamespace maybeNamespace
   pure filtered
   where
     filterByType Nothing ts = ts
     filterByType (Just typ) ts = filter (\t -> taskType t == typ) ts
     filterByParent Nothing ts = ts
     filterByParent (Just pid) ts = filter (\t -> taskParent t == Just pid) ts
+    filterByStatus Nothing ts = ts
+    filterByStatus (Just status) ts = filter (\t -> taskStatus t == status) ts
+    filterByNamespace Nothing ts = ts
+    filterByNamespace (Just ns) ts = filter (\t -> taskNamespace t == Just ns) ts
 
 -- Get ready tasks (not blocked by dependencies)
 getReadyTasks :: IO [Task]