Add section separators to updatedb.js for better readability

Added clear visual section separators to tools/updatedb.js (608 lines):

Sections added:
- GeoIP Database Updater (header)
- Dependencies
- Configuration
- Utility Functions (mkdir, tryFixingLine, CSVtoArray)
- HTTP Configuration (getHTTPOptions)
- Database Download Functions (check, fetch, extract)
- Data Processing Functions (processCountryData, processCityData, processCityDataNames)
- Main Processing Dispatcher (processData)
- Checksum Management (updateChecksum)
- Main Execution Flow

Benefits:
- Easy navigation through 600+ lines of code
- Clear separation of concerns
- Better code maintainability
- Improved developer experience

All 94 tests pass. ESLint clean.

Author: claude

tools/updatedb.js

@@ -1,7 +1,14 @@
-// Fetches and converts MaxMind lite databases
+// ============================================================================
+// GeoIP Database Updater
+// Fetches and converts MaxMind GeoLite2 databases
+// ============================================================================
 
 'use strict';
 
+// ============================================================================
+// Dependencies
+// ============================================================================
+
 const { name, version } = require('../package.json');
 const UserAgent = `Mozilla/5.0 (compatible; ${name}/${version}; +https://github.com/sefinek/geoip-lite2)`;
 
@@ -19,6 +26,10 @@ const AdmZip = require('adm-zip');
 const utils = require('../lib/utils.js');
 const { Address6, Address4 } = require('ip-address');
 
+// ============================================================================
+// Configuration
+// ============================================================================
+
 const args = process.argv.slice(2);
 let license_key = args.find(arg => arg.match(/^license_key=[a-zA-Z0-9]+/) !== null);
 if (typeof license_key === 'undefined' && typeof process.env.LICENSE_KEY !== 'undefined') {
@@ -67,6 +78,10 @@ const databases = [{
 	dest: ['geoip-city-names.dat', 'geoip-city.dat', 'geoip-city6.dat'],
 }];
 
+// ============================================================================
+// Utility Functions
+// ============================================================================
+
 function mkdir(dirName) {
 	const dir = path.dirname(dirName);
 	if (!fs.existsSync(dir)) fs.mkdirSync(dir);
@@ -118,6 +133,10 @@ function CSVtoArray(text) {
 	return a;
 }
 
+// ============================================================================
+// HTTP Configuration
+// ============================================================================
+
 function getHTTPOptions(downloadUrl) {
 	const parsedUrl = new URL(downloadUrl);
 	const options = {
@@ -140,6 +159,10 @@ function getHTTPOptions(downloadUrl) {
 	return options;
 }
 
+// ============================================================================
+// Database Download Functions
+// ============================================================================
+
 function check(database, cb) {
 	if (args.indexOf('force') !== -1) {
 		// We are forcing database upgrade,
@@ -292,6 +315,10 @@ function processLookupCountry(src, cb) {
 	});
 }
 
+// ============================================================================
+// Data Processing Functions
+// ============================================================================
+
 async function processCountryData(src, dest) {
 	let lines = 0;
 	const dataFile = path.join(dataPath, dest);
@@ -538,6 +565,10 @@ function processCityDataNames(src, dest, cb) {
 	rl.on('close', cb);
 }
 
+// ============================================================================
+// Main Processing Dispatcher
+// ============================================================================
+
 function processData(database, cb) {
 	if (database.skip) return cb(null, database);
 
@@ -573,6 +604,10 @@ function processData(database, cb) {
 	}
 }
 
+// ============================================================================
+// Checksum Management
+// ============================================================================
+
 function updateChecksum(database, cb) {
 	if (database.skip || !database.checkValue) return cb(); // Don't need to update checksums because it was not fetched or did not change
 
@@ -582,6 +617,10 @@ function updateChecksum(database, cb) {
 	});
 }
 
+// ============================================================================
+// Main Execution Flow
+// ============================================================================
+
 if (!license_key) {
 	console.error('ERROR: Missing license_key');
 	process.exit(1);