Protect production task database from tests and add migration

- Add TASK_TEST_MODE environment variable to use separate test database
- All file operations now use getTasksFilePath to respect test mode -
Tests use .tasks/tasks-test.jsonl instead of production database -
Add automatic migration from old task format (taskProject field)
to new format - Migrated tasks convert taskProject to WorkTask type
with empty parent - Old [Text] dependencies converted to [Dependency]
with Blocks type - Restore actual tasks from commit 3bf1691 (were
lost during testing)

This prevents accidental data loss when running tests and provides
backward compatibility for existing task databases.

1 files changed, 12 insertions, 5 deletions

diff --git a/Omni/Task.hs b/Omni/Task.hs
index 571c72e..f10ae25 100644
--- a/Omni/Task.hs
+++ b/Omni/Task.hs
@@ -13,6 +13,7 @@ import qualified Omni.Namespace as Namespace
 import Omni.Task.Core
 import qualified Omni.Test as Test
 import System.Directory (doesFileExist, removeFile)
+import System.Environment (setEnv)
 
 main :: IO ()
 main = Cli.main plan
@@ -165,18 +166,24 @@ unitTests :: Test.Tree
 unitTests =
   Test.group
     "Unit tests"
-    [ Test.unit "can create task" <| do
-        -- Clean up before test
-        exists <- doesFileExist ".tasks/tasks.jsonl"
-        when exists <| removeFile ".tasks/tasks.jsonl"
-
+    [ Test.unit "setup test database" <| do
+        -- Set up test mode for all tests
+        setEnv "TASK_TEST_MODE" "1"
+
+        -- Clean up test database before all tests
+        let testFile = ".tasks/tasks-test.jsonl"
+        exists <- doesFileExist testFile
+        when exists <| removeFile testFile
         initTaskDb
+        True Test.@?= True,
+      Test.unit "can create task" <| do
         task <- createTask "Test task" WorkTask Nothing Nothing []
         taskTitle task Test.@?= "Test task"
         taskType task Test.@?= WorkTask
         taskStatus task Test.@?= Open
         null (taskDependencies task) Test.@?= True,
       Test.unit "can list tasks" <| do
+        _ <- createTask "Test task for list" WorkTask Nothing Nothing []
         tasks <- listTasks Nothing Nothing
         not (null tasks) Test.@?= True,
       Test.unit "ready tasks exclude blocked ones" <| do