feat(auth): add trusted-device 30-day 2FA skip (backend)

Adds a "trust this device" option to the 2FA challenge: on success, mints a
random token (only its SHA-256 hash is stored), sets it as a new httpOnly,
Secure, SameSite=Strict cookie, and records a TrustedDevice row. AuthController
checks that cookie for the exact signing-in user before gating on 2FA -- a
mismatched user, expired, or revoked device falls through to the normal 2FA
prompt, never errors. TwoFactorController also exposes list/revoke/revoke-all
endpoints for managing trusted devices, scoped to the owning user.

Schema added via the existing raw-SQL reconciler (SQLite + MySQL dialects),
not EF migrations, matching this repo's established pattern.

JobTrackerApi/Controllers/TwoFactorController.cs

@@ -44,7 +44,8 @@ public sealed class TwoFactorController : ControllerBase
     public sealed record VerifySetupResult(bool Enabled, IReadOnlyList<string> RecoveryCodes);
     public sealed record StatusResult(bool Enabled, DateTimeOffset? EnabledAtUtc);
     public sealed record RecoveryCodesResult(IReadOnlyList<string> RecoveryCodes);
-    public sealed record ChallengeRequest(string PendingToken, string Code);
+    public sealed record ChallengeRequest(string PendingToken, string Code, bool TrustDevice = false);
+    public sealed record TrustedDeviceDto(int Id, string? DeviceLabel, DateTimeOffset CreatedAtUtc, DateTimeOffset LastSeenAtUtc, DateTimeOffset ExpiresAtUtc, bool IsCurrentDevice);
 
     [HttpPost("setup")]
     [Authorize(AuthenticationSchemes = "local")]
@@ -202,9 +203,74 @@ public sealed class TwoFactorController : ControllerBase
 
         _pending.Resolve(pendingToken, consume: true);
         await AppSessionIssuer.IssueAsync(Request, Response, _tokens, user, session.RememberMe, cancellationToken);
+
+        if (request.TrustDevice)
+        {
+            await TrustedDeviceService.IssueAsync(_db, Request, Response, user.Id, cancellationToken);
+        }
+
         return Ok(new AuthController.AuthSessionResult(true, "local"));
     }
 
+    [HttpGet("trusted-devices")]
+    [Authorize(AuthenticationSchemes = "local")]
+    public async Task<IActionResult> ListTrustedDevices(CancellationToken cancellationToken)
+    {
+        var user = await _users.GetUserAsync(User);
+        if (user is null) return Unauthorized();
+
+        var currentHash = TrustedDeviceService.CurrentDeviceTokenHash(Request);
+        var devices = await _db.TrustedDevices
+            .Where(x => x.UserId == user.Id)
+            .OrderByDescending(x => x.LastSeenAtUtc)
+            .Select(x => new TrustedDeviceDto(x.Id, x.DeviceLabel, x.CreatedAtUtc, x.LastSeenAtUtc, x.ExpiresAtUtc, currentHash != null && x.TokenHash == currentHash))
+            .ToListAsync(cancellationToken);
+
+        return Ok(devices);
+    }
+
+    [HttpDelete("trusted-devices/{id:int}")]
+    [Authorize(AuthenticationSchemes = "local")]
+    public async Task<IActionResult> RevokeTrustedDevice(int id, CancellationToken cancellationToken)
+    {
+        var user = await _users.GetUserAsync(User);
+        if (user is null) return Unauthorized();
+
+        var device = await _db.TrustedDevices.FirstOrDefaultAsync(x => x.Id == id && x.UserId == user.Id, cancellationToken);
+        if (device is null) return NotFound();
+
+        var currentHash = TrustedDeviceService.CurrentDeviceTokenHash(Request);
+        var isCurrentDevice = currentHash != null && string.Equals(device.TokenHash, currentHash, StringComparison.Ordinal);
+
+        _db.TrustedDevices.Remove(device);
+        await _db.SaveChangesAsync(cancellationToken);
+
+        if (isCurrentDevice)
+        {
+            TrustedDeviceService.ClearCookie(Request, Response);
+        }
+
+        return NoContent();
+    }
+
+    [HttpPost("trusted-devices/revoke-all")]
+    [Authorize(AuthenticationSchemes = "local")]
+    public async Task<IActionResult> RevokeAllTrustedDevices(CancellationToken cancellationToken)
+    {
+        var user = await _users.GetUserAsync(User);
+        if (user is null) return Unauthorized();
+
+        var devices = await _db.TrustedDevices.Where(x => x.UserId == user.Id).ToListAsync(cancellationToken);
+        if (devices.Count > 0)
+        {
+            _db.TrustedDevices.RemoveRange(devices);
+            await _db.SaveChangesAsync(cancellationToken);
+        }
+
+        TrustedDeviceService.ClearCookie(Request, Response);
+        return NoContent();
+    }
+
     private static bool VerifyCode(string base32Secret, string? code)
     {
         code = (code ?? string.Empty).Trim();