feat(export): Replace CSV export with standardized JSON format

- Add contactsToExportJson utility function for standardized data export
- Replace CSV export with JSON format in DataExportSection
- Update file extension and MIME type to application/json
- Remove Dexie-specific export logic in favor of unified SQLite/Dexie approach
- Update success notifications to reflect JSON format
- Add TypeScript interfaces for export data structure

This change improves data portability and standardization by:
- Using a consistent JSON format for data export/import
- Supporting both SQLite and Dexie databases
- Including all contact fields in export
- Properly handling contactMethods as stringified JSON
- Maintaining backward compatibility with existing import tools

Security: No sensitive data exposure, maintains existing access controls

src/services/migrationService.ts

@@ -31,8 +31,6 @@ export class MigrationService {
     sqlQuery: (sql: string) => Promise<T>,
     extractMigrationNames: (result: T) => Set<string>,
   ): Promise<void> {
-    // eslint-disable-next-line no-console
-    console.log("Will run migrations");
 
     // Create migrations table if it doesn't exist
     const result0 = await sqlExec(`
@@ -42,29 +40,21 @@ export class MigrationService {
         executed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
       );
     `);
-    // eslint-disable-next-line no-console
-    console.log("Created migrations table", JSON.stringify(result0));
 
     // Get list of executed migrations
     const result1: T = await sqlQuery("SELECT name FROM migrations;");
     const executedMigrations = extractMigrationNames(result1);
-    // eslint-disable-next-line no-console
-    console.log(
-      "Executed migration select",
-      JSON.stringify(executedMigrations),
-    );
+
 
     // Run pending migrations in order
     for (const migration of this.migrations) {
       if (!executedMigrations.has(migration.name)) {
-        const result2 = await sqlExec(migration.sql);
-        // eslint-disable-next-line no-console
-        console.log("Executed migration", JSON.stringify(result2));
-        const result3 = await sqlExec(
+        await sqlExec(migration.sql);
+
+        await sqlExec(
           `INSERT INTO migrations (name) VALUES ('${migration.name}')`,
         );
-        // eslint-disable-next-line no-console
-        console.log("Updated migrations table", JSON.stringify(result3));
+
       }
     }
   }