Refactor server package: split handlers and routes into separate files

- Move all handler functions to handlers.go
- Move setupRoutes to routes.go
- Clean up server.go to only contain core server logic
- Add missing GetASDetails and GetPrefixDetails to mockStore for tests
- Fix linter errors (magic numbers, unused parameters, blank lines)

internal/routewatch/app_integration_test.go

@@ -201,6 +201,26 @@ func (m *mockStore) GetASInfoForIP(ip string) (*database.ASInfo, error) {
 	}, nil
 }
 
+// GetASDetails mock implementation
+func (m *mockStore) GetASDetails(asn int) (*database.ASN, []database.LiveRoute, error) {
+	m.mu.Lock()
+	defer m.mu.Unlock()
+
+	// Check if ASN exists
+	if asnInfo, exists := m.ASNs[asn]; exists {
+		// Return empty prefixes for now
+		return asnInfo, []database.LiveRoute{}, nil
+	}
+
+	return nil, nil, database.ErrNoRoute
+}
+
+// GetPrefixDetails mock implementation
+func (m *mockStore) GetPrefixDetails(prefix string) ([]database.LiveRoute, error) {
+	// Return empty routes for now
+	return []database.LiveRoute{}, nil
+}
+
 func TestRouteWatchLiveFeed(t *testing.T) {
 
 	// Create mock database