Enhance HRIStudio with immersive experiment designer and comprehensive documentation updates

- Introduced a new immersive experiment designer using React Flow, providing a professional-grade visual flow editor for creating experiments.
- Added detailed documentation for the flow designer connections and ordering system, emphasizing its advantages and implementation details.
- Updated existing documentation to reflect the latest features and improvements, including a streamlined README and quick reference guide.
- Consolidated participant type definitions into a new file for better organization and clarity.

Features:
- Enhanced user experience with a node-based interface for experiment design.
- Comprehensive documentation supporting new features and development practices.

Breaking Changes: None - existing functionality remains intact.

src/components/dashboard/study-guard.tsx

@@ -1,6 +1,8 @@
 "use client";
 
-import { useStudyContext } from "~/lib/study-context";
+import { AlertTriangle, Building, Loader2 } from "lucide-react";
+import Link from "next/link";
+import { Button } from "~/components/ui/button";
 import {
   Card,
   CardContent,
@@ -8,9 +10,7 @@ import {
   CardHeader,
   CardTitle,
 } from "~/components/ui/card";
-import { Button } from "~/components/ui/button";
-import { Building, AlertTriangle, Loader2 } from "lucide-react";
-import Link from "next/link";
+import { useStudyContext } from "~/lib/study-context";
 
 interface StudyGuardProps {
   children: React.ReactNode;