feat(users): OTP delivery method picker on user creation + post-login agreement

Create User dialog now has a mandatory Email/Mobile OTP delivery method
picker (styled as a pill toggle) alongside the existing fields.

Adds a new post-login agreement acceptance dialog: right after the existing
2FA flow (TwoFactorAuthenticationComponent) succeeds, or immediately after
login for users without 2FA, the user must accept the bank's current
agreement/disclaimer at least once before reaching the app.

Also adds a "Manage User Agreement" admin screen (System section) to publish
versioned agreement text without a code deploy.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

src/app/users/user-form-dialog/user-form-dialog.component.scss

@@ -126,6 +126,12 @@ $purple: #7c3aed;
   display: grid;
   grid-template-columns: 1fr 1fr;
   gap: 10px 14px;
+
+  // A field placed right after the grid (e.g. OTP Delivery Method, which spans full width
+  // and isn't part of the 2-column layout) needs its own breathing room above it.
+  + .ufd-field {
+    margin-top: 12px;
+  }
 }
 
 .ufd-field {
@@ -268,6 +274,57 @@ $purple: #7c3aed;
   }
 }
 
+.ufd-otp-methods {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 8px;
+}
+
+.ufd-otp-method {
+  display: inline-flex;
+  align-items: center;
+  gap: 7px;
+  height: 36px;
+  padding: 0 14px;
+  border: 1px solid #cbd5e1;
+  background: #fff;
+  border-radius: 999px;
+  color: #475569;
+  font-size: 12.5px;
+  font-weight: 600;
+  cursor: pointer;
+  transition: all 0.12s;
+
+  fa-icon {
+    font-size: 12px;
+  }
+
+  // stylelint-disable-next-line selector-no-qualifying-type
+  input[type='radio'] {
+    // Visually hidden but still focusable/clickable for accessibility - the pill itself
+    // carries the selected state via .is-selected, matching .ufd-role's pattern.
+    position: absolute;
+    opacity: 0;
+    width: 0;
+    height: 0;
+  }
+
+  &:hover {
+    border-color: #94a3b8;
+    color: $navy;
+  }
+
+  &.is-selected {
+    background: rgb(30 136 229 / 12%);
+    border-color: $blue;
+    color: $blue-d;
+
+    fa-icon {
+      color: $blue;
+    }
+  }
+}
+
 .ufd-hint {
   display: flex;
   align-items: center;