Update TODO.txt: Mark stack status tasks as completed

Author: dagjomar

TODO.txt

@@ -13,12 +13,12 @@
 - Detect and warn about potential stack issues
 
 ## Stack Status & Overview
-- Add `git stack status` command showing:
-  - Current active stack
-  - All branches in the stack with latest commits
+- ✅ Add `git stack status` command showing: (COMPLETED)
+  - ✅ Current active stack (COMPLETED)
+  - ✅ All branches in the stack with latest commits (COMPLETED)
   - Remote sync status for each branch
-  - Conflict detection between stack branches
-  - Stack depth and health metrics
+  - ✅ Conflict detection between stack branches (COMPLETED)
+  - ✅ Stack depth and health metrics (COMPLETED)
 
 ## Advanced Stack Operations
 - `git stack rebase` - Rebase entire stack onto main