fix(team): toggle team mode on/off based on --team flag

- crab ws N --team: adds Team Mode section to CLAUDE.md
- crab ws N: removes Team Mode section (single-agent mode)

This makes --team a proper toggle rather than a one-time setup.

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: MrFlounder

src/crabcode

@@ -1301,15 +1301,18 @@ open_workspace() {
   local dev_cmd=$(get_pane_command "server")
   local claude_cmd=$(get_pane_command "main")
 
-  # If team mode, write team context to CLAUDE.md for interactive session
+  # Handle team mode: add or remove team section from CLAUDE.md
+  local team_file="$dir/.claude/CLAUDE.md"
   if [ -n "${TEAM_PROMPT:-}" ]; then
-    local team_file="$dir/.claude/CLAUDE.md"
+    # Team mode ON: add team section
     mkdir -p "$dir/.claude"
 
-    # Write team instructions to CLAUDE.md (overwrites any existing team section)
+    # Remove existing team section if present, then append new one
     if [ -f "$team_file" ]; then
-      # Remove existing team section if present, then append
-      sed -i '' '/^## Team Mode$/,/^## /{ /^## Team Mode$/d; /^## /!d; }' "$team_file" 2>/dev/null || true
+      # Remove team section (from ## Team Mode to next ## or end of file)
+      sed -i '' '/^## Team Mode$/,/^## [^T]/{ /^## Team Mode$/d; /^## [^T]/!d; }' "$team_file" 2>/dev/null || true
+      # Also handle if Team Mode is last section (no following ##)
+      sed -i '' '/^## Team Mode$/,$d' "$team_file" 2>/dev/null || true
     fi
 
     cat >> "$team_file" << EOF
@@ -1320,7 +1323,16 @@ $TEAM_PROMPT
 
 When the user provides a task, spawn teammates as needed using the Task tool.
 EOF
-    echo -e "${MAGENTA}Team mode enabled - instructions written to .claude/CLAUDE.md${NC}"
+    echo -e "${MAGENTA}Team mode enabled${NC}"
+  else
+    # Team mode OFF: remove team section if it exists
+    if [ -f "$team_file" ]; then
+      # Remove team section
+      sed -i '' '/^## Team Mode$/,/^## [^T]/{ /^## Team Mode$/d; /^## [^T]/!d; }' "$team_file" 2>/dev/null || true
+      sed -i '' '/^## Team Mode$/,$d' "$team_file" 2>/dev/null || true
+      # Clean up trailing whitespace
+      sed -i '' -e :a -e '/^\n*$/{$d;N;ba' -e '}' "$team_file" 2>/dev/null || true
+    fi
   fi
 
   # Port override if needed