feat: implement external environmental data display components

- Add WeatherWidget for current weather conditions
- Add TideDisplay for tide times and heights
- Add WaterQualityIndicator for EPA water quality data
- Add BeachQualityDisplay for beach ratings and certifications
- Add BiodiversityInfo for marine biodiversity information
- Add EnvironmentalDataPanel composite component
- Create externalDataService for API integration
- Add types for external environmental data
- Create demo page at /demo/environmental-data
- Add comprehensive README documentation

Fulfills requirements 11.1, 11.2, 11.3, 11.4, 11.6, 11.7
Completes task 19 from implementation plan

src/types/index.ts

@@ -179,3 +179,65 @@ export interface QuantityAggregation {
   count: number;
   percentage: number;
 }
+
+// External environmental data types
+export interface WeatherData {
+  temperature: number; // Celsius
+  feelsLike: number;
+  humidity: number; // percentage
+  windSpeed: number; // m/s
+  windDirection: number; // degrees
+  description: string;
+  icon: string;
+  timestamp: Date;
+}
+
+export interface TideData {
+  tides: Array<{
+    time: Date;
+    height: number; // meters
+    type: 'high' | 'low';
+  }>;
+  nextTide?: {
+    time: Date;
+    height: number;
+    type: 'high' | 'low';
+  };
+}
+
+export interface WaterQualityData {
+  status: 'excellent' | 'good' | 'sufficient' | 'poor' | 'unknown';
+  lastUpdated?: Date;
+  parameters?: {
+    bacteria?: number;
+    ph?: number;
+    temperature?: number;
+  };
+  source?: string;
+}
+
+export interface BeachQualityData {
+  rating: 'blue-flag' | 'green-coast' | 'excellent' | 'good' | 'adequate' | 'poor' | 'unknown';
+  awards?: string[];
+  facilities?: string[];
+  lastInspection?: Date;
+}
+
+export interface BiodiversityData {
+  species?: Array<{
+    name: string;
+    scientificName?: string;
+    status?: string;
+  }>;
+  protectedArea?: boolean;
+  habitatType?: string;
+  conservationStatus?: string;
+}
+
+export interface ExternalEnvironmentalData {
+  weather?: WeatherData;
+  tides?: TideData;
+  waterQuality?: WaterQualityData;
+  beachQuality?: BeachQualityData;
+  biodiversity?: BiodiversityData;
+}