feat: complete release readiness work

- consolidate API ownership and remove dead vendor code

- add Stripe billing, learning paths, and public CV hardening

- add migration, recovery, security, audit, and browser gates

JobTrackerApi/Models/SystemEmailSettings.cs

@@ -0,0 +1,15 @@
+namespace JobTrackerApi.Models;
+
+public sealed class SystemEmailSettings
+{
+    public int Id { get; set; } = 1;
+    public bool? Enabled { get; set; }
+    public string? SmtpHost { get; set; }
+    public int? SmtpPort { get; set; }
+    public string? SmtpUser { get; set; }
+    public string? SmtpPassword { get; set; }
+    public string? From { get; set; }
+    public string? FromName { get; set; }
+    public bool? SmtpEnableSsl { get; set; }
+    public int? SmtpTimeoutMs { get; set; }
+}