feat(developers): simplify timezone dropdown and make email optional

Replace 100+ raw system timezones with curated list of 26 major zones
with browser auto-detection via Intl API. Remove email requirement since
applicants receive a @silverlabs.uk address — fallback to username@silverlabs.uk
when no personal email is provided.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

BlazorApp/Components/Pages/Developers.razor

@@ -2,6 +2,7 @@
 @using SilverLabs.Website.Models
 @using SilverLabs.Website.Services
 @inject DeveloperApplicationService ApplicationService
+@inject IJSRuntime JS
 @rendermode InteractiveServer
 
 <PageTitle>Join the Team - SilverLabs</PageTitle>
@@ -85,8 +86,9 @@
                         </div>
 
                         <div class="form-group">
-                            <label for="email">Email Address</label>
+                            <label for="email">Email Address (optional)</label>
                             <InputText id="email" @bind-Value="_application.Email" class="form-input" placeholder="jane@example.com" />
+                            <span class="form-hint">Leave blank to use your @@silverlabs.uk address</span>
                             <ValidationMessage For="() => _application.Email" />
                         </div>
 
@@ -256,10 +258,35 @@
 
     private readonly string[] _availablePlatforms = { "Windows", "macOS", "Linux", "Android", "iOS", "Other" };
 
-    private static readonly List<(string Id, string Label)> _timezones = TimeZoneInfo.GetSystemTimeZones()
-        .OrderBy(tz => tz.BaseUtcOffset)
-        .Select(tz => (tz.Id, $"(UTC{(tz.BaseUtcOffset >= TimeSpan.Zero ? "+" : "")}{tz.BaseUtcOffset:hh\\:mm}) {tz.DisplayName}"))
-        .ToList();
+    private static readonly List<(string Id, string Label)> _timezones = new()
+    {
+        ("Pacific/Midway",       "(UTC-11:00) Midway Island"),
+        ("Pacific/Honolulu",     "(UTC-10:00) Hawaii"),
+        ("America/Anchorage",    "(UTC-09:00) Alaska"),
+        ("America/Los_Angeles",  "(UTC-08:00) Pacific Time (US & Canada)"),
+        ("America/Denver",       "(UTC-07:00) Mountain Time (US & Canada)"),
+        ("America/Chicago",      "(UTC-06:00) Central Time (US & Canada)"),
+        ("America/New_York",     "(UTC-05:00) Eastern Time (US & Canada)"),
+        ("America/Caracas",      "(UTC-04:00) Venezuela"),
+        ("America/Halifax",      "(UTC-04:00) Atlantic Time (Canada)"),
+        ("America/Sao_Paulo",    "(UTC-03:00) Brazil"),
+        ("Atlantic/South_Georgia","(UTC-02:00) Mid-Atlantic"),
+        ("Atlantic/Azores",      "(UTC-01:00) Azores"),
+        ("Europe/London",        "(UTC+00:00) London, Dublin, Lisbon"),
+        ("Europe/Berlin",        "(UTC+01:00) Berlin, Paris, Amsterdam"),
+        ("Europe/Bucharest",     "(UTC+02:00) Bucharest, Helsinki, Athens"),
+        ("Europe/Moscow",        "(UTC+03:00) Moscow, Istanbul"),
+        ("Asia/Dubai",           "(UTC+04:00) Dubai, Baku"),
+        ("Asia/Karachi",         "(UTC+05:00) Karachi, Tashkent"),
+        ("Asia/Kolkata",         "(UTC+05:30) Mumbai, New Delhi"),
+        ("Asia/Dhaka",           "(UTC+06:00) Dhaka, Almaty"),
+        ("Asia/Bangkok",         "(UTC+07:00) Bangkok, Jakarta"),
+        ("Asia/Shanghai",        "(UTC+08:00) Beijing, Singapore, Perth"),
+        ("Asia/Tokyo",           "(UTC+09:00) Tokyo, Seoul"),
+        ("Australia/Sydney",     "(UTC+10:00) Sydney, Melbourne"),
+        ("Pacific/Noumea",       "(UTC+11:00) Solomon Islands"),
+        ("Pacific/Auckland",     "(UTC+12:00) Auckland, Fiji"),
+    };
 
     private static readonly System.Text.RegularExpressions.Regex UsernamePattern =
         new(@"^[a-zA-Z0-9_-]{3,30}$", System.Text.RegularExpressions.RegexOptions.Compiled);
@@ -269,6 +296,26 @@
     private bool IsSubmitDisabled =>
         _submitting || _usernameCheckState == UsernameCheckState.Taken || _usernameCheckState == UsernameCheckState.Checking;
 
+    protected override async Task OnAfterRenderAsync(bool firstRender)
+    {
+        if (firstRender && string.IsNullOrEmpty(_application.Timezone))
+        {
+            try
+            {
+                var detectedTz = await JS.InvokeAsync<string>("eval", "Intl.DateTimeFormat().resolvedOptions().timeZone");
+                if (!string.IsNullOrEmpty(detectedTz) && _timezones.Any(tz => tz.Id == detectedTz))
+                {
+                    _application.Timezone = detectedTz;
+                    StateHasChanged();
+                }
+            }
+            catch
+            {
+                // Browser may not support Intl API — ignore
+            }
+        }
+    }
+
     private void SelectRole(ApplicationRole role)
     {
         _application.Role = role;

BlazorApp/Models/DeveloperApplication.cs

@@ -8,9 +8,8 @@ public class DeveloperApplication
     [StringLength(100, MinimumLength = 2)]
     public string FullName { get; set; } = string.Empty;
 
-    [Required(ErrorMessage = "Email is required")]
     [EmailAddress(ErrorMessage = "Invalid email address")]
-    public string Email { get; set; } = string.Empty;
+    public string? Email { get; set; }
 
     [Required(ErrorMessage = "Username is required")]
     [RegularExpression(@"^[a-zA-Z0-9_-]{3,30}$", ErrorMessage = "Username must be 3-30 characters, letters, numbers, hyphens and underscores only")]

BlazorApp/Services/DeveloperApplicationService.cs

@@ -48,11 +48,16 @@ public class DeveloperApplicationService
     {
         try
         {
+            // Use silverlabs.uk address when no personal email provided
+            var effectiveEmail = string.IsNullOrWhiteSpace(application.Email)
+                ? $"{application.DesiredUsername}@silverlabs.uk"
+                : application.Email.Trim();
+
             // 1. Register user on SilverDESK
             var registerPayload = new
             {
                 username = application.DesiredUsername,
-                email = application.Email,
+                email = effectiveEmail,
                 password = application.Password,
                 fullName = application.FullName
             };
@@ -111,7 +116,7 @@ public class DeveloperApplicationService
                     userId,
                     ticketId,
                     fullName = application.FullName,
-                    email = application.Email,
+                    email = effectiveEmail,
                     desiredUsername = application.DesiredUsername,
                     timezone = application.Timezone,
                     appliedRole = application.Role.ToString(),
@@ -126,29 +131,29 @@ public class DeveloperApplicationService
 
                 if (appResponse.IsSuccessStatusCode)
                 {
-                    _logger.LogInformation("DeveloperApplication record created for {Email}", application.Email);
+                    _logger.LogInformation("DeveloperApplication record created for {Email}", effectiveEmail);
                 }
                 else
                 {
                     var appError = await appResponse.Content.ReadAsStringAsync();
                     _logger.LogWarning("Failed to create DeveloperApplication record for {Email}: {StatusCode} - {Body}",
-                        application.Email, appResponse.StatusCode, appError);
+                        effectiveEmail, appResponse.StatusCode, appError);
                 }
             }
             catch (Exception ex)
             {
                 _logger.LogWarning(ex, "Failed to create DeveloperApplication record for {Email} — user and ticket were created successfully",
-                    application.Email);
+                    effectiveEmail);
             }
 
             _logger.LogInformation("Developer application submitted for {Email} as {Role} — user registered and ticket created",
-                application.Email, application.Role);
+                effectiveEmail, application.Role);
 
             return (true, "Application submitted successfully! Your SilverDESK account has been created.", token);
         }
         catch (Exception ex)
         {
-            _logger.LogError(ex, "Error submitting developer application for {Email}", application.Email);
+            _logger.LogError(ex, "Error submitting developer application for {Username}", application.DesiredUsername);
             return (false, "Unable to connect to the application service. Please try again later.", null);
         }
     }
@@ -177,12 +182,16 @@ public class DeveloperApplicationService
 
     private static string FormatTicketBody(DeveloperApplication app)
     {
+        var effectiveEmail = string.IsNullOrWhiteSpace(app.Email)
+            ? $"{app.DesiredUsername}@silverlabs.uk"
+            : app.Email.Trim();
+
         var sb = new StringBuilder();
         sb.AppendLine("## Developer Program Application");
         sb.AppendLine();
         sb.AppendLine($"**Role:** {app.Role}");
         sb.AppendLine($"**Full Name:** {app.FullName}");
-        sb.AppendLine($"**Email:** {app.Email}");
+        sb.AppendLine($"**Email:** {effectiveEmail}");
         sb.AppendLine($"**Desired Username:** {app.DesiredUsername}");
         sb.AppendLine($"**Timezone:** {app.Timezone}");
         sb.AppendLine();