Fix gum multi-select TTY access issue

Fixed subprocess call to allow gum direct terminal access for interactive UI.

Problem:
- capture_output=True was preventing gum from accessing the TTY
- Gum needs stdin/stderr connected to terminal for interactive display
- Error: "could not open a new TTY: open /dev/tty"

Solution:
- Changed from capture_output=True to explicit stdout=PIPE
- Set stdin=None and stderr=None to allow direct terminal access
- Gum can now properly display interactive selection menu

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

utils.py

@@ -188,9 +188,12 @@ def gum_multi_select(
         return []
 
     try:
+        # gum needs direct terminal access - don't redirect stdin/stderr
         result = subprocess.run(
             ['gum', 'choose', '--no-limit', '--header', header] + options,
-            capture_output=True,
+            stdout=subprocess.PIPE,
+            stderr=None,  # Let stderr go to terminal
+            stdin=None,   # Let gum access the terminal directly
             text=True,
             timeout=300  # 5 minute timeout
         )