fix(chat): forward polish + scrollbar + image preview + media tabs

- #4: forward modal buttons now branded (bzc-* un-scoped from .bz-confirm); target
  rows get real checkboxes + border highlight; selected MESSAGES highlight in green
  with a filled tick (distinct from blue bubbles), checkbox on every message.
- #5: forwarded messages show an italic 'Forwarded from <origin>' label; new fwd_from
  column preserves the true origin across re-forwards.
- #6: image-preview arrows are smaller (32px) chevron icons, clear of the image
  (image max 82vw); icons.js?v=5.
- #10: image preview now opens ABOVE the media modal (z 9900) and Esc/close returns
  to the media view instead of closing everything.
- #11: Media/Links/Docs active tab underline is brand-blue, not green.
- #2: chat-list + conversation scrollbars 6px, stepper arrows hidden; pagination adds
  a cooldown + overflow-anchor:none so scrolling up no longer sticks/jumps.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

server/routes.js

@@ -11,7 +11,7 @@ const PUSH = require('./push');
 const MSG_MAX = 4000;
 const parseMentions = (s) => { if (!s) return []; try { const a = JSON.parse(s); return Array.isArray(a) ? a : []; } catch { return []; } };
 const SYSTEM_SENDER = '__system__';
-const msgDTO = (m) => ({ id: m.id, from: m.sender_id, to: m.recipient_id, conversation_id: m.conversation_id || null, body: m.deleted ? '' : m.body, created_at: m.created_at, read_at: m.read_at, delivered_at: m.delivered_at || null, reply_to: m.deleted ? null : (m.reply_to || null), mentions: parseMentions(m.mentions), evt: m.msg_type || null, deleted: !!m.deleted, system: m.sender_id === SYSTEM_SENDER || !!m.msg_type });
+const msgDTO = (m) => ({ id: m.id, from: m.sender_id, to: m.recipient_id, conversation_id: m.conversation_id || null, body: m.deleted ? '' : m.body, created_at: m.created_at, read_at: m.read_at, delivered_at: m.delivered_at || null, reply_to: m.deleted ? null : (m.reply_to || null), mentions: parseMentions(m.mentions), evt: m.msg_type || null, fwd_from: m.deleted ? null : (m.fwd_from || null), deleted: !!m.deleted, system: m.sender_id === SYSTEM_SENDER || !!m.msg_type });
 function namesFor(teamId){ const o = {}; for (const x of R.users.listByTenant(teamId)) o[x.id] = x.name || x.email; return o; }
 // Next future occurrence (same time-of-day) of a weekly-recurring meeting; searches 14 days ahead.
 function nextOccurrence(baseTs, days, nowTs){ const b = new Date(baseTs); const hh = b.getHours(), mm = b.getMinutes(); const s = new Date(nowTs); for (let i = 0; i <= 14; i++){ const d = new Date(s.getFullYear(), s.getMonth(), s.getDate() + i, hh, mm, 0, 0); if (days.indexOf(d.getDay()) >= 0 && d.getTime() > nowTs) return d.getTime(); } return baseTs; }
@@ -1367,8 +1367,9 @@ route('POST', '/api/messages/forward', async (req, res) => {
     else { tid = R.users.resolve(tid); if (!tid || !R.users.inTenant(tid, u.team_id)) continue; }
     for (const m of srcs) {
       const nid = A.token(16);
-      if (isGroup) R.messages.send({ id: nid, teamId: u.team_id, senderId: u.id, recipientId: '', body: m.body, attachmentId: m.attachment_id, conversationId: tid });
-      else R.messages.send({ id: nid, teamId: u.team_id, senderId: u.id, recipientId: tid, body: m.body, attachmentId: m.attachment_id });
+      const origin = m.fwd_from || names[m.sender_id] || 'Unknown'; // preserve the true origin across re-forwards
+      if (isGroup) R.messages.send({ id: nid, teamId: u.team_id, senderId: u.id, recipientId: '', body: m.body, attachmentId: m.attachment_id, conversationId: tid, fwdFrom: origin });
+      else R.messages.send({ id: nid, teamId: u.team_id, senderId: u.id, recipientId: tid, body: m.body, attachmentId: m.attachment_id, fwdFrom: origin });
       const dto = buildMsgDTO(R.messages.byId(nid), names, u.id);
       const push = { type: 'chat-message', message: { ...dto, fromName: u.name || u.email } };
       if (isGroup) { for (const mid of R.conversations.members(tid)) { try { CHAT.pushToUser(mid, push); } catch (_) {} } }