digest email: replace reply/reaction counts with relay URL

- Replace `{{Replies}}`/`{{Reactions}}` stat items in digest.mjml with
  a single `{{RelayUrl}}` item showing the posting relay domain
- src/digest.ts: add `RelayUrl` to template variables, derive from
  existing `relayByEventId` map; strip unused `spec`, `getParentId`,
  `repliesByParentId`, and `context` destructure
- test/digest-reply-stats.test.ts: update assertion to check
  `parentEntry.RelayUrl` instead of `Replies`/`Reactions`
- script/render-preview.mjs: update sample data to use `RelayUrl`

script/render-preview.mjs

@@ -24,8 +24,7 @@ const sample = {
       Icon: 'https://i.pravatar.cc/150?img=32',
       Name: 'carol',
       Content: '<p>Does anyone know how relay-based groups work?</p>',
-      Replies: 5,
-      Reactions: 8,
+      RelayUrl: 'relay.damus.io',
     },
     {
       Link: 'https://app.flotilla.social/spaces/nos.lol/community?at=1700000000',
@@ -34,8 +33,7 @@ const sample = {
       Name: 'bob',
       Content:
         '<p>Excited to share our new community space on Flotilla! <a href="https://flotilla.social">Check it out</a>.</p>',
-      Replies: 14,
-      Reactions: 32,
+      RelayUrl: 'nos.lol',
     },
   ],
   unsubscribeUrl: 'https://app.flotilla.social/unsubscribe?token=abc123',

src/digest.ts

@@ -1,6 +1,5 @@
 import { neventEncode, decode } from 'nostr-tools/nip19'
 import {
-  spec,
   sortBy,
   groupBy,
   displayList,
@@ -10,7 +9,6 @@ import { parse, truncate, renderAsHtml } from '@welshman/content'
 import {
   TrustedEvent,
   normalizeRelayUrl,
-  getParentId,
   NOTE,
   COMMENT,
   REACTION,
@@ -50,23 +48,23 @@ export class Digest {
     const getEventVariables = (event: TrustedEvent) => {
       const parsed = truncate(parse(event), { minLength: 400, maxLength: 800, mediaLength: 50 })
 
+      const relayUrl = data.relayByEventId.get(event.id)
+
       return {
-        Link: buildLink(event, handler, data.relayByEventId.get(event.id)),
+        Link: buildLink(event, handler, relayUrl),
         Timestamp: formatter.format(secondsToDate(event.created_at)),
         Icon: profilesByPubkey.get().get(event.pubkey)?.picture,
         Name: displayProfileByPubkey(event.pubkey),
         Content: renderAsHtml(parsed, { createElement, renderEntity }).toString(),
-        Replies:
-          repliesByParentId.get(event.id)?.filter((e) => [COMMENT, NOTE].includes(e.kind))
-            ?.length || 0,
-        Reactions: repliesByParentId.get(event.id)?.filter(spec({ kind: REACTION }))?.length || 0,
+        RelayUrl: relayUrl
+          ? normalizeRelayUrl(relayUrl).replace(/^wss:\/\//, '').replace(/\/$/, '')
+          : '',
       }
     }
 
-    const { events, context } = data
+    const { events } = data
     const formatter = getFormatter()
     const handler = await this.loadHandler()
-    const repliesByParentId = groupBy(getParentId, context)
     const eventsByPubkey = groupBy((e) => e.pubkey, events)
     const userProfile = profilesByPubkey.get().get(this.sub.pubkey)
     const sorted = sortBy((e) => e.created_at, events).slice(0, 100)

src/emails/digest.mjml

@@ -64,10 +64,7 @@
             <div class="event-content">{{{Content}}}</div>
             <div class="event-stats">
               <span class="stat-item">
-                {{Replies}} replies
-              </span>
-              <span class="stat-item">
-                {{Reactions}} reactions
+                Posted to {{RelayUrl}}
               </span>
             </div>
           </div>

test/digest-reply-stats.test.ts

@@ -1,6 +1,5 @@
 import { describe, it, expect, vi, beforeEach } from 'vitest'
 import type { TrustedEvent } from '@welshman/util'
-import { spec } from '@welshman/lib'
 
 // ── Shared state accessible from both vi.mock factories and test body ──────
 const mockRepo = vi.hoisted(() => {
@@ -159,9 +158,7 @@ describe('digest reply/reaction stats', () => {
     expect(latest.length).toBeGreaterThanOrEqual(1)
 
     const parentEntry = latest[0]
-    // When context includes reply/reaction events loaded from the repository,
-    // Replies should be >= 1 and Reactions >= 1
-    expect(parentEntry.Replies).toBeGreaterThanOrEqual(1)
-    expect(parentEntry.Reactions).toBeGreaterThanOrEqual(1)
+    // RelayUrl should be the relay domain stripped of protocol and trailing slash
+    expect(parentEntry.RelayUrl).toBe('relay.example.com')
   })
 })