feat: implement comprehensive gamification, analytics, and leaderboard system

This commit adds a complete gamification system with analytics dashboards,
leaderboards, and enhanced badge tracking functionality.

Backend Features:
- Analytics API with overview, user stats, activity trends, top contributors,
  and street statistics endpoints
- Leaderboard API supporting global, weekly, monthly, and friends views
- Profile API for viewing and managing user profiles
- Enhanced gamification service with badge progress tracking and user stats
- Comprehensive test coverage for analytics and leaderboard endpoints
- Profile validation middleware for secure profile updates

Frontend Features:
- Analytics dashboard with multiple tabs (Overview, Activity, Personal Stats)
- Interactive charts for activity trends and street statistics
- Leaderboard component with pagination and timeframe filtering
- Badge collection display with progress tracking
- Personal stats component showing user achievements
- Contributors list for top performing users
- Profile management components (View/Edit)
- Toast notifications integrated throughout
- Comprehensive test coverage for Leaderboard component

Enhancements:
- User model enhanced with stats tracking and badge management
- Fixed express.Router() capitalization bug in users route
- Badge service improvements for better criteria matching
- Removed unused imports in Profile component

This feature enables users to track their contributions, view community
analytics, compete on leaderboards, and earn badges for achievements.

🤖 Generated with OpenCode

Co-Authored-By: AI Assistant <noreply@opencode.ai>

frontend/src/components/profile/ProfileView.js

@@ -0,0 +1,71 @@
+import React, { useState, useEffect, useContext } from \"react\";
+import { useParams, Link } from \"react-router-dom\";
+import axios from \"axios\";
+const { AuthContext } = require(\"../../context/AuthContext\");
+
+const ProfileView = () => {
+  const { userId } = useParams();
+  const { auth } = useContext(AuthContext);
+  const [profile, setProfile] = useState(null);
+  const [loading, setLoading] = useState(true);
+  const [error, setError] = useState(null);
+
+  useEffect(() => {
+    const fetchProfile = async () => {
+      try {
+        const res = await axios.get((/api/profile/${userId}`);
+        setProfile(res.data);
+      } catch (err) {
+        setError(err.response?.ager = == auth.user._id;
+
+  return (
+    <div className=\"container mt-5\">
+      <div className=\"row\">
+        <div className=\"col-md-4 text-center\">
+          <img 
+            src={`npame"} id: auth.user._id });
+          setProfile(res.data);
+        } catch (err) {
+          setError(err.response?.data?.msg || \"Error fetching profile\");
+        }
+        setLoading(false);
+      };
+
+      fetchProfile();
+    }, [userId]);
+
+  if (loading) {
+    return <div className=\"container\"><p>Loading profile...</p></div>;
+  }
+
+  if (error) {
+    return <div className=\"container\"><div className=\"alert alert-danger\">{error}</div></div>;
+  }
+
+  if (!profile) {
+    return <div className=\"container\"><p>Profile not found.</p></div>;
+  }
+
+  const { name, avatar, bio, location, website, social, preferences } = profile;
+  const isOwnProfile = auth.isAuthenticated && auth.user._id === userId;
+
+  return (
+    <div className=\"container mt-5\">
+      <div className=\"row\">
+        <div className=\"col-md-4 text-center\">
+          <img 
+            src={avatar || \"/logo512.png\"} 
+            alt={`${name}\'s avatar`} 
+            className=\"img-fluid rounded-circle mb-3\" 
+            style={{ width: \"150px\", height: \"150px\" }}
+          />
+          <h3>{name}</h3>
+          {location && <p className=\"text-muted\">{location}</p>}
+          {isOwnProfile && (
+            <Link to=\"/profile/edit\" className=\"btn btn-primary mb-3\">Edit Profile</Link>
+          )}
+        </div>
+        <div className=\"col-md-8\">
+          <div className=\"card\">
+            <div className=\"card-body\">
+