task: prettier tree visualization and flag ordering fixes

- Implement box-drawing characters (├──, └──, │) for
task tree visualization - Fix 'task create' flag ordering by using
[options] in docopt (same as 'task list') - Document TASK_TEST_MODE
environment variable in AGENTS.md Testing section - Add test case for
multi-flag ordering on 'task create' - Clean up test tasks polluted
in production database

All 29 tests passing.

Amp-Thread-ID:
https://ampcode.com/threads/T-4e6225cf-3e78-4538-963c-5377bbbccee8
Co-authored-by: Amp <amp@ampcode.com>

4 files changed, 39 insertions, 15 deletions

diff --git a/.tasks/tasks.jsonl b/.tasks/tasks.jsonl
index e069305..10715dd 100644
--- a/.tasks/tasks.jsonl
+++ b/.tasks/tasks.jsonl
@@ -22,7 +22,7 @@
 {"taskCreatedAt":"2025-11-09T13:05:18.445111257Z","taskDependencies":[],"taskId":"t-PqMc17","taskNamespace":"Omni/Task.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Add enhanced dependency types (blocks, discovered-from, related)","taskType":"WorkTask","taskUpdatedAt":"2025-11-09T13:05:18.50495798Z"}
 {"taskCreatedAt":"2025-11-09T13:05:18.543055749Z","taskDependencies":[],"taskId":"t-PqMBuS","taskNamespace":"Omni/Task.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Protect production database from tests","taskType":"WorkTask","taskUpdatedAt":"2025-11-09T13:05:18.602787251Z"}
 {"taskCreatedAt":"2025-11-09T13:05:18.64074361Z","taskDependencies":[],"taskId":"t-PqN0Uu","taskNamespace":"Omni/Task.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Add migration support for old task format","taskType":"WorkTask","taskUpdatedAt":"2025-11-09T13:05:18.703048004Z"}
-{"taskCreatedAt":"2025-11-09T14:22:32.038937583Z","taskDependencies":[],"taskId":"t-Uumhrq","taskNamespace":"Omni/Task.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Open","taskTitle":"Investigate and implement prettier tree drawing with box characters","taskType":"WorkTask","taskUpdatedAt":"2025-11-09T14:22:32.038937583Z"}
+{"taskCreatedAt":"2025-11-09T14:22:32.038937583Z","taskDependencies":[],"taskId":"t-Uumhrq","taskNamespace":"Omni/Task.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Investigate and implement prettier tree drawing with box characters","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T18:40:33.764590135Z"}
 {"taskCreatedAt":"2025-11-09T16:48:40.260201423Z","taskDependencies":[],"taskId":"t-143KQl2","taskNamespace":"Biz/PodcastItLater.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Open","taskTitle":"PodcastItLater: Path to Paid Product","taskType":"WorkTask","taskUpdatedAt":"2025-11-09T16:48:40.260201423Z"}
 {"taskCreatedAt":"2025-11-09T16:48:47.076581674Z","taskDependencies":[],"taskId":"t-144drAE","taskNamespace":"Biz/PodcastItLater.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Adopt Bootstrap CSS for UI improvements","taskType":"WorkTask","taskUpdatedAt":"2025-11-09T17:00:05.424532832Z"}
 {"taskCreatedAt":"2025-11-09T16:48:47.237113366Z","taskDependencies":[],"taskId":"t-144e7lF","taskNamespace":"Biz/PodcastItLater.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Add Stripe integration for billing","taskType":"WorkTask","taskUpdatedAt":"2025-11-09T23:04:23.856763018Z"}
@@ -117,9 +117,5 @@
 {"taskCreatedAt":"2025-11-20T15:25:27.424518009Z","taskDependencies":[],"taskId":"t-YBRpHe","taskNamespace":null,"taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"CLI parsing fails with multiple flags","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T15:58:11.990663284Z"}
 {"taskCreatedAt":"2025-11-20T15:25:27.720568105Z","taskDependencies":[],"taskId":"t-YBSEIe","taskNamespace":"Omni/Task.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Namespace filter broken","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T15:58:12.269456015Z"}
 {"taskCreatedAt":"2025-11-20T15:25:27.948491266Z","taskDependencies":[],"taskId":"t-YBTC0p","taskNamespace":null,"taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Discovered-from flag broken","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T15:58:12.685064773Z"}
-{"taskCreatedAt":"2025-11-20T15:57:33.643445015Z","taskDependencies":[],"taskId":"t-10IdDer","taskNamespace":"Omni/Test.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Open","taskTitle":"Test multi-flag","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T15:57:33.643445015Z"}
-{"taskCreatedAt":"2025-11-20T15:57:33.870558362Z","taskDependencies":[],"taskId":"t-10IeAjy","taskNamespace":null,"taskParent":null,"taskPriority":"P2","taskStatus":"Open","taskTitle":"Test","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T15:57:33.870558362Z"}
-{"taskCreatedAt":"2025-11-20T15:57:34.151624098Z","taskDependencies":[],"taskId":"t-10IfLqS","taskNamespace":"Omni/Test.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Open","taskTitle":"Test","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T15:57:34.151624098Z"}
 {"taskCreatedAt":"2025-11-20T15:58:11.740041636Z","taskDependencies":[],"taskId":"t-10KNtTF","taskNamespace":null,"taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Docopt flag order matters incorrectly","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T18:35:44.798128524Z"}
-{"taskCreatedAt":"2025-11-20T16:00:40.024108922Z","taskDependencies":[],"taskId":"t-10UPFmb","taskNamespace":null,"taskParent":null,"taskPriority":"P1","taskStatus":"Open","taskTitle":"High priority bug","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T16:00:40.024108922Z"}
-{"taskCreatedAt":"2025-11-20T16:00:40.275992513Z","taskDependencies":[],"taskId":"t-10UQISP","taskNamespace":null,"taskParent":null,"taskPriority":"P3","taskStatus":"Open","taskTitle":"Low priority polish","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T16:00:40.275992513Z"}
+{"taskCreatedAt":"2025-11-20T18:44:29.330834039Z","taskDependencies":[{"depId":"t-Uumhrq","depType":"DiscoveredFrom"}],"taskId":"t-1bE2r3q","taskNamespace":"Omni/Task.hs","taskParent":null,"taskPriority":"P2","taskStatus":"Done","taskTitle":"Document TASK_TEST_MODE in AGENTS.md","taskType":"WorkTask","taskUpdatedAt":"2025-11-20T18:53:22.852670919Z"}
diff --git a/AGENTS.md b/AGENTS.md
index b668758..6ff1ebf 100644
--- a/AGENTS.md
+++ b/AGENTS.md
@@ -435,7 +435,7 @@ Each line in `tasks.jsonl` is a JSON object representing a task.
 
 ### Testing and Development
 
-**IMPORTANT**: When writing or testing code that modifies tasks, use the test database:
+**CRITICAL**: When manually testing task functionality (like tree visualization, flag ordering, etc.), you MUST use the test database:
 
 ```bash
 # Set test mode to protect production database
@@ -444,6 +444,7 @@ export TASK_TEST_MODE=1
 # Now all task operations use .tasks/tasks-test.jsonl
 task create "Test task" --type=task
 task list
+task tree
 
 # Unset when done
 unset TASK_TEST_MODE
@@ -451,7 +452,7 @@ unset TASK_TEST_MODE
 
 **The test suite automatically uses test mode** - you don't need to set it manually when running `task test` or `bild --test Omni/Task.hs`.
 
-**Never run destructive tests against the production database** (`.tasks/tasks.jsonl`) as this will delete real task data.
+**NEVER run manual tests against the production database** (`.tasks/tasks.jsonl`). This pollutes it with test data that must be manually cleaned up. Always use `TASK_TEST_MODE=1` for experimentation.
 
 ## Integration with Git
 
diff --git a/Omni/Task.hs b/Omni/Task.hs
index eeca4c6..6d2da71 100644
--- a/Omni/Task.hs
+++ b/Omni/Task.hs
@@ -38,7 +38,7 @@ task
 
 Usage:
   task init [--quiet]
-  task create <title> [--type=<type>] [--parent=<id>] [--priority=<p>] [--deps=<ids>] [--dep-type=<type>] [--discovered-from=<id>] [--namespace=<ns>] [--json]
+  task create <title> [options]
   task list [options]
   task ready [--json]
   task show <id> [--json]
@@ -453,5 +453,14 @@ cliTests =
         let result = Docopt.parseArgs help ["sync"]
         case result of
           Left err -> Test.assertFailure <| "Failed to parse 'sync': " <> show err
-          Right args -> args `Cli.has` Cli.command "sync" Test.@?= True
+          Right args -> args `Cli.has` Cli.command "sync" Test.@?= True,
+      Test.unit "create with flags in different order" <| do
+        let result = Docopt.parseArgs help ["create", "Test", "--json", "--priority=1", "--namespace=Omni/Task"]
+        case result of
+          Left err -> Test.assertFailure <| "Failed to parse 'create' with reordered flags: " <> show err
+          Right args -> do
+            args `Cli.has` Cli.command "create" Test.@?= True
+            args `Cli.has` Cli.longOption "json" Test.@?= True
+            Cli.getArg args (Cli.longOption "priority") Test.@?= Just "1"
+            Cli.getArg args (Cli.longOption "namespace") Test.@?= Just "Omni/Task"
     ]
diff --git a/Omni/Task/Core.hs b/Omni/Task/Core.hs
index 1dc31a8..f463040 100644
--- a/Omni/Task/Core.hs
+++ b/Omni/Task/Core.hs
@@ -10,6 +10,7 @@ import qualified Data.Aeson as Aeson
 import qualified Data.Aeson.KeyMap as KM
 import Data.Aeson.Types (parseMaybe)
 import qualified Data.ByteString.Lazy.Char8 as BLC
+import qualified Data.List as List
 import qualified Data.Text as T
 import qualified Data.Text.IO as TIO
 import Data.Time (UTCTime, diffTimeToPicoseconds, getCurrentTime, utctDayTime)
@@ -324,9 +325,19 @@ showTaskTree maybeId = do
     printEpicTree allTasks task = printTreeNode allTasks task 0
 
     printTreeNode :: [Task] -> Task -> Int -> IO ()
-    printTreeNode allTasks task indent = do
-      let prefix = T.pack (replicate (indent * 2) ' ')
-          children = filter (\t -> taskParent t == Just (taskId task)) allTasks
+    printTreeNode allTasks task indent = printTreeNode' allTasks task indent []
+
+    printTreeNode' :: [Task] -> Task -> Int -> [Bool] -> IO ()
+    printTreeNode' allTasks task indent ancestry = do
+      let children = filter (\t -> taskParent t == Just (taskId task)) allTasks
+          -- Build tree prefix using box-drawing characters
+          prefix =
+            if indent == 0
+              then ""
+              else
+                let ancestorPrefixes = map (\hasMore -> if hasMore then "│   " else "    ") (List.init ancestry)
+                    myPrefix = if List.last ancestry then "├── " else "└── "
+                 in T.pack <| concat ancestorPrefixes ++ myPrefix
           -- For epics, show progress count [completed/total]; for tasks, show status checkbox
           statusStr = case taskType task of
             Epic ->
@@ -349,8 +360,15 @@ showTaskTree maybeId = do
               else taskTitle task
       putText <| prefix <> taskId task <> " " <> statusStr <> " " <> nsStr <> truncatedTitle
 
-      -- Print children
-      traverse_ (\child -> printTreeNode allTasks child (indent + 1)) children
+      -- Print children with updated ancestry
+      let indexedChildren = zip [1 ..] children
+          totalChildren = length children
+      traverse_
+        ( \(idx, child) ->
+            let hasMoreSiblings = idx < totalChildren
+             in printTreeNode' allTasks child (indent + 1) (ancestry ++ [hasMoreSiblings])
+        )
+        indexedChildren
 
 -- Helper to print a task
 printTask :: Task -> IO ()