web: spam check in call history

SD5 (14 §9.5): each incoming call keeps what the spam check knew when it
ended (saved answers and the FTC list only, no new lookup), so the badge
stays in call history after the saved answer expires. Hidden when the
viewer's contacts name the number. New admin guide page, spam-check.md.

Follow-up: the owner's checks with real keys and a real call (14 §9).

apps/web/src/pages/admin/CallsPage.tsx

@@ -11,6 +11,7 @@ import {
   type CallFilter,
 } from '@selfphoneng/shared';
 import { callsApi, extensionsApi, recordingsApi } from '../../api/client.ts';
+import { SpamNote } from '../../components/SpamNote.tsx';
 import { Alert, Button, Field, inputClass } from '../../components/ui.tsx';
 
 export const fmtNumber = (n: string | null) =>
@@ -170,6 +171,7 @@ export function CallsPage() {
                 {c.answeredBy && (
                   <span className="text-zinc-500"> · answered by {c.answeredBy.name}</span>
                 )}
+                <SpamNote check={c.spam} />
               </span>
               <StatusBadge status={c.status} />
               <span className="w-12 text-right tabular-nums">{fmtDuration(c.talkSeconds)}</span>

apps/web/src/pages/user/MyCallsPage.tsx

@@ -9,6 +9,7 @@ import { Alert, Button } from '../../components/ui.tsx';
 import { softphone } from '../../softphone/SoftphoneEngine.ts';
 import { DIRECTION_TEXT, StatusBadge, fmtDuration, fmtNumber } from '../admin/CallsPage.tsx';
 import { AddToContacts, useContactName } from './ContactsPage.tsx';
+import { SpamNote } from '../../components/SpamNote.tsx';
 
 /** The other side of the call, from where I sit. */
 export const otherParty = (c: MyCallDto) =>
@@ -84,6 +85,7 @@ export function MyCallsPage() {
                 {!known && other.number && c.direction !== 'internal' && (
                   <AddToContacts number={other.number} name={other.name} />
                 )}
+                {c.myRole === 'in' && !known && <SpamNote check={c.spam} />}
               </span>
               {c.recordingId && (
                 <audio