R2 accounts are safe: email by password and code, recovery only to it, sessions that end

Completion program R2 (docs/ROADMAP.md, 2026-10-17).

- An email address is set only with the password and a 6-digit code sent to it: /clientapi/user/email, /email/verify,
  /email/remove and GET /clientapi/user/account (EmailVerification: an hour, five tries, the code's hash only;
  EmailVerificationJob through the new IMailer). The request answers one sentence whether or not the address is free,
  and nothing goes to an address another login verified. The old POST /clientapi/user/update, which changed the
  address with neither and said when one was taken, answers 422.
- Recovery writes only to a verified address; migration _019 keeps the addresses given before verification existed.
- A changed password ends every session and every persona token, and answers a new JWT for the device that changed it.
- Sessions: every JWT carries its session's id ("si", kept by sniff/again). GET /clientapi/user/logout, which did
  nothing, ends that session alone (RootUser.EndedSessions, until its tokens would expire); POST
  /clientapi/user/logout/everywhere ends them all.
- AppConfiguration:HashingOptions was never bound, so passwords were hashed at the default 9789 iterations: it is
  bound now, at 210,000, and a hash made at other iterations is made again at the next sign-in (matched on the old
  hash, so two sign-ins never undo each other).
- Recovery and verification codes expire through TTL indexes; EmailVerification is never in a backup.
- AppConfigurationService reads appsettings as they are now, not the copy older builds saved in Mongo on first boot.
- ViewUserSettings and RootUserSettings carry SavedAt, so a client signing in keeps its own theme until one saved.
- Pasture: peers/mailpit.sh (Mailpit 1.31.4 as mailpit.test) receives PrivaPub's mail; recovery links open
  https://decepub.test. scenarios/accounts.sh, in sweep batch A, checks all of the above (28 checks).

Verified: dotnet build PrivaPub.sln -c Release; the pasture with gts and mailpit: accounts 28/28 and gts, 91 passed,
0 failed.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01WpVCoDeM1qUTRp4fXQdfof

PrivaPub.ClientModels/User/AccountForms.cs

@@ -0,0 +1,53 @@
+using PrivaPub.ClientModels.Resources;
+
+using System.ComponentModel;
+using System.ComponentModel.DataAnnotations;
+
+namespace PrivaPub.ClientModels.User
+{
+	// The login's email address, set only with its password and only once a code sent to it comes back
+	// (/clientapi/user/email, /email/verify).
+	public class EmailChangeForm
+	{
+		[Required(ErrorMessageResourceName = "Required", ErrorMessageResourceType = typeof(ErrorsResource)),
+			EmailAddress(ErrorMessageResourceName = "InvalidEmail", ErrorMessageResourceType = typeof(ErrorsResource)),
+			StringLength(254, ErrorMessageResourceName = "MaxLengthString", ErrorMessageResourceType = typeof(ErrorsResource)),
+			Display(Name = "Email", ResourceType = typeof(FieldsNameResource))]
+		public string Email { get; set; }
+
+		[Required(ErrorMessageResourceName = "Required", ErrorMessageResourceType = typeof(ErrorsResource)),
+			DataType(DataType.Password),
+			PasswordPropertyText(true),
+			StringLength(Constants.MaxPasswordLength, ErrorMessageResourceName = "MaxLengthString", ErrorMessageResourceType = typeof(ErrorsResource)),
+			Display(Name = "Password", ResourceType = typeof(FieldsNameResource))]
+		public string Password { get; set; }
+	}
+
+	public class EmailCodeForm
+	{
+		[Required(ErrorMessageResourceName = "Required", ErrorMessageResourceType = typeof(ErrorsResource)),
+			StringLength(16, MinimumLength = 6, ErrorMessageResourceName = "StringLengthMinMax", ErrorMessageResourceType = typeof(ErrorsResource)),
+			Display(Name = "RecoveryCode", ResourceType = typeof(FieldsNameResource))]
+		public string Code { get; set; }
+	}
+
+	// what only the login's password may do (removing its email address)
+	public class PasswordForm
+	{
+		[Required(ErrorMessageResourceName = "Required", ErrorMessageResourceType = typeof(ErrorsResource)),
+			DataType(DataType.Password),
+			PasswordPropertyText(true),
+			StringLength(Constants.MaxPasswordLength, ErrorMessageResourceName = "MaxLengthString", ErrorMessageResourceType = typeof(ErrorsResource)),
+			Display(Name = "Password", ResourceType = typeof(FieldsNameResource))]
+		public string Password { get; set; }
+	}
+
+	public class ViewAccount
+	{
+		public string UserName { get; set; }
+		public string Email { get; set; }
+		public bool IsEmailValidated { get; set; } = false;
+		public string PendingEmail { get; set; }//waiting for its code
+		public DateTime CreatedAt { get; set; }
+	}
+}