fix: improve worktree/session handling in cmd_start, cmd_continue, and cmd_init

cmd_continue:
- If worktree is missing but session exists, remove stale session and call cmd_start automatically
- This allows automatic recovery without user intervention

cmd_start:
- Check BOTH worktree AND session existence
- If only worktree exists (not session): remove worktree, recreate both
- If only session exists (not worktree): remove session, recreate both
- If both exist: tell user to use continue

cmd_init --force:
- Now actually destroys existing base and pm-agent sessions before reinitializing

Daemon:
- Fixed wrong path in check_task_completion ($HOME/.kugetsu-worktrees -> $WORKTREES_DIR)

skills/kugetsu/scripts/kugetsu-session.sh

@@ -83,10 +83,9 @@ EOF
     if [ -n "$existing_base" ] && [ "$existing_base" != "null" ]; then
         if [ "$force" = true ]; then
             echo "Warning: Reinitializing sessions (force mode)" >&2
-            echo "Destroying all sessions, worktrees, and logs..." >&2
+            echo "Destroying existing sessions..." >&2
             cmd_destroy --base -y 2>/dev/null || true
             cmd_destroy --pm-agent -y 2>/dev/null || true
-            rm -f "$LOGS_DIR"/*.log 2>/dev/null || true
         else
             echo "Error: Base session already exists: $existing_base" >&2
             echo "Use --force to reinitialize" >&2