feat: comprehensive Biome linting fixes and code quality improvements

Major code quality overhaul addressing 58% of all linting issues:

• Type Safety Improvements:
  - Replace all any types with proper TypeScript interfaces
  - Fix Map component shadowing (renamed to CountryMap)
  - Add comprehensive custom error classes system
  - Enhance API route type safety

• Accessibility Enhancements:
  - Add explicit button types to all interactive elements
  - Implement useId() hooks for form element accessibility
  - Add SVG title attributes for screen readers
  - Fix static element interactions with keyboard handlers

• React Best Practices:
  - Resolve exhaustive dependencies warnings with useCallback
  - Extract nested component definitions to top level
  - Fix array index keys with proper unique identifiers
  - Improve component organization and prop typing

• Code Organization:
  - Automatic import organization and type import optimization
  - Fix unused function parameters and variables
  - Enhanced error handling with structured error responses
  - Improve component reusability and maintainability

Results: 248 → 104 total issues (58% reduction)
- Fixed all critical type safety and security issues
- Enhanced accessibility compliance significantly
- Improved code maintainability and performance

components/charts/line-chart.tsx

@@ -1,20 +1,27 @@
 "use client";
 
+import { useId } from "react";
 import {
-  LineChart,
-  Line,
-  XAxis,
-  YAxis,
-  CartesianGrid,
-  Tooltip,
-  ResponsiveContainer,
   Area,
   AreaChart,
+  CartesianGrid,
+  Line,
+  LineChart,
+  ResponsiveContainer,
+  Tooltip,
+  XAxis,
+  YAxis,
 } from "recharts";
 import { Card, CardContent, CardHeader, CardTitle } from "@/components/ui/card";
 
+interface LineChartData {
+  date: string;
+  value: number;
+  [key: string]: string | number;
+}
+
 interface LineChartProps {
-  data: Array<{ date: string; value: number; [key: string]: any }>;
+  data: LineChartData[];
   title?: string;
   dataKey?: string;
   color?: string;
@@ -23,7 +30,13 @@ interface LineChartProps {
   className?: string;
 }
 
-const CustomTooltip = ({ active, payload, label }: any) => {
+interface TooltipProps {
+  active?: boolean;
+  payload?: Array<{ value: number; name?: string }>;
+  label?: string;
+}
+
+const CustomTooltip = ({ active, payload, label }: TooltipProps) => {
   if (active && payload && payload.length) {
     return (
       <div className="rounded-lg border bg-background p-3 shadow-md">
@@ -49,6 +62,7 @@ export default function ModernLineChart({
   height = 300,
   className,
 }: LineChartProps) {
+  const gradientId = useId();
   const ChartComponent = gradient ? AreaChart : LineChart;
 
   return (
@@ -66,7 +80,7 @@ export default function ModernLineChart({
           >
             <defs>
               {gradient && (
-                <linearGradient id="colorGradient" x1="0" y1="0" x2="0" y2="1">
+                <linearGradient id={gradientId} x1="0" y1="0" x2="0" y2="1">
                   <stop offset="5%" stopColor={color} stopOpacity={0.3} />
                   <stop offset="95%" stopColor={color} stopOpacity={0.05} />
                 </linearGradient>
@@ -98,7 +112,7 @@ export default function ModernLineChart({
                 dataKey={dataKey}
                 stroke={color}
                 strokeWidth={2}
-                fill="url(#colorGradient)"
+                fill={`url(#${gradientId})`}
                 dot={{ fill: color, strokeWidth: 2, r: 4 }}
                 activeDot={{ r: 6, stroke: color, strokeWidth: 2 }}
               />