simplify: prune dead code, dedup gmail send, drop neutered log stubs

- Remove no-op log stubs (logGmail, logAutomation, logSecurity, logSystem)
  and ~17 callsites; dead counters in tickets.js and gmail-poll.js go too
- Dedup three near-identical Gmail send paths into sendThreadedEmail helper
- Drop dead Mongoose fields: broccoliniTicketId, lastSyncedBroccoliniArticleId,
  renameCount, renameWindowStart, reminderSent, staffChannelId,
  unclaimedRemindersSent, lastMessageAuthorIsStaff
- Drop dead config fields and their .env.example entries
- Inline api/botClient.js (3-line wrapper, 2 callers)
- Trim unused exports across utils.js, tickets.js, configSchema.js, debugLog.js
- Fix handlers/messages.js to use isStaff() — old partial check ignored
  ADDITIONAL_STAFF_ROLES, so those members were treated as customers
- Drop unused deps p-queue + dotenv-expand; move mongodb to devDependencies

Net: -583 LOC source + -57 LOC lockfile. All 23 modules load clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

handlers/commands.js

@@ -3,7 +3,6 @@
  */
 const {
   ChannelType,
-  ActionRowBuilder,
   ButtonBuilder,
   ButtonStyle,
   AttachmentBuilder,
@@ -18,7 +17,7 @@ const { sendTicketNotificationEmail } = require('../services/gmail');
 const { getTicketActionRow } = require('../utils/ticketComponents');
 const { enqueueRename, enqueueMove, enqueueSend } = require('../services/channelQueue');
 const { setNotifyDm } = require('../services/staffSettings');
-const { logTicketEvent, logSecurity, logError } = require('../services/debugLog');
+const { logError } = require('../services/debugLog');
 const { pendingCloses } = require('./pendingCloses');
 
 const Ticket = mongoose.model('Ticket');
@@ -51,7 +50,6 @@ async function requireStaffRole(interaction) {
     content: `This command is only available to the support team (${roleMention}).`,
     ephemeral: true
   });
-  logSecurity('Unauthorized command attempt', interaction.user, interaction.commandName).catch(() => {});
   return true;
 }
 
@@ -130,7 +128,6 @@ async function runEscalation(interaction, ticket, nextTier, reason) {
         ticket,
         null,
         emailBody,
-        escalatorName,
         interaction.user.id
       );
     } catch (emailErr) {