feat(backend): Add cable graph service and data collectors

## Changelog

### New Features

#### Cable Graph Service
- Add cable_graph.py for finding shortest path between landing points
- Implement haversine distance calculation for great circle distances
- Support for dateline crossing (longitude normalization)
- NetworkX-based graph for optimal path finding

#### Data Collectors
- Add ArcGISCableCollector for fetching submarine cable data from ArcGIS GeoJSON API
- Add FAOLandingPointCollector for fetching landing point data from FAO CSV API

### Backend Changes

#### API Updates
- auth.py: Update authentication logic
- datasources.py: Add datasource endpoints and management
- visualization.py: Add visualization API endpoints
- config.py: Update configuration settings
- security.py: Improve security settings

#### Models & Schemas
- task.py: Update task model with new fields
- token.py: Update token schema

#### Services
- collectors/base.py: Improve base collector with better error handling
- collectors/__init__.py: Register new collectors
- scheduler.py: Update scheduler logic
- tasks/scheduler.py: Add task scheduling

### Frontend Changes
- AppLayout.tsx: Improve layout component
- index.css: Add global styles
- DataSources.tsx: Enhance data sources management page
- vite.config.ts: Add Vite configuration for earth module

frontend/vite.config.ts

@@ -1,5 +1,6 @@
 import { defineConfig } from 'vite'
 import react from '@vitejs/plugin-react'
+import path from 'path'
 
 export default defineConfig({
   plugins: [react()],
@@ -18,5 +19,14 @@ export default defineConfig({
         secure: false,
       },
     },
+    fs: {
+      allow: ['..'],
+    },
+  },
+  publicDir: 'public',
+  resolve: {
+    alias: {
+      '@': path.resolve(__dirname, './src'),
+    },
   },
 })