Give public Chat room pages a real meta description (#311)

ddiff --git a/server/web/pages.js b/server/web/pages.js
iindex 46fbb07..ae3969c 100644
---- a/server/web/pages.js
++++ b/server/web/pages.js
@@@ -827,10 +827,15 @@ ${people}
          const work = rooms.isWorkspace(room) ? await require('../rooms/workspace').list(room, me, { limit: 40 }) : null;
          const aiHere = ais.length ? `<p class="oc-ai-here">${ICONS.spark}<span>${ais.map((a) => `<strong>${esc(a.name)}</strong> <span class="oc-muted oc-ai-model">(${esc(aiMembers.modelOf(a))})</span>`).join(', ')} ${ais.length > 1 ? 'are' : 'is'} here: write ${ais.map((a) => `<code>@${esc(a.handle)}</code>`).join(' or ')} to ask</span></p>` : '';
          const memberCount = (await rooms.publicRoom(room)).members;
++        // A public room's own line when it has one long enough to read as a description; otherwise its name, size
++        // and what the page is for. Escaped by the layout's head builder like every other description.
++        const topic = typeof room.topic === 'string' ? room.topic.trim() : '';
++        const description = topic.length >= 40 ? topic
++            : `${room.name}: a ${room.visibility === 'public' ? 'public' : 'private'} room on OpenVibe.Chat with ${memberCount} ${memberCount === 1 ? 'member' : 'members'}. Read along, or sign in to talk.`;
          await page(req, res, 200, {
              actor, title: room.name, path: `/r/${room.slug}`, active: 'rooms', robots: room.visibility === 'public' ? 'index, follow' : 'noindex, nofollow', script: true, callScript: callReady, feedView: !!feed,
              footer: 'compact', scripts: ais.length ? ['vibe-md.js'] : [], wide: !!work,
--            description: room.topic || `${room.name}, a ${isCall ? 'call' : room.kind === 'system' ? 'announcements' : 'chat'} room on OpenVibe.`,
++            description,
              page: { view: 'room', room: room.slug, kind: room.kind, pics: pictures.enabled() ? pictures.publicUrl() : null, ai: ais.map((a) => a.handle), latest: msgs.length ? msgs[msgs.length - 1].id : 0, me: me ? me.id : null, moderate: can.moderate, post: can.post, role: can.role,
                  ...(callReady ? { call: { channel: `room-${room.slug}`, join: can.join, talk: can.talk } } : {}) },
              body: `<header class="oc-room-head">
ddiff --git a/test/room-kinds.test.js b/test/room-kinds.test.js
iindex 3e64ace..4080433 100644
---- a/test/room-kinds.test.js
++++ b/test/room-kinds.test.js
@@@ -297,6 +297,12 @@ t('the site: kinds on the rooms page, the call panel, roles and attachments in s
      assert.match(r.text, /id="oc-call-join" hidden>Listen in</);
      assert.match(r.text, /you are a participant/);
  
++    // Room pages carry a real description: the room's own line when it has one, else its name and size.
++    assert.match((await page('/r/tea-talk', null)).text, /<meta name="description" content="Tea Talk: a public room on OpenVibe\.Chat with \d+ member/);
++    const topic = 'Tea, biscuits and the small talk that makes a Tuesday afternoon go faster.';
++    assert.strictEqual((await api('PATCH', '/tea-talk', own, { topic })).status, 200);
++    assert.ok((await page('/r/tea-talk', null)).text.includes(`<meta name="description" content="${topic}">`), 'the room\'s own topic is the description');
++
      r = await page('/r/open-stage/settings', own);
      for (const role of ['moderator', 'speaker', 'participant', 'viewer', 'blocked']) assert.ok(r.text.includes(`>${role}</option>`), role);
      assert.ok(!r.text.includes('>member</option>'), 'call rooms have no members, they have participants');