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>

services/debugLog.js

@@ -58,13 +58,6 @@ async function logWarn(context, message, overrideClient = null) {
   await sendToChannel(CONFIG.DEBUGGING_CHANNEL_ID, embed, overrideClient);
 }
 
-// --- logEvent (generic – posts to any configured channel) ---
-
-async function logEvent(channelConfigKey, embed, overrideClient = null) {
-  const channelId = CONFIG[channelConfigKey];
-  await sendToChannel(channelId, embed, overrideClient);
-}
-
 // --- logTicketEvent ---
 
 async function logTicketEvent(action, fields, interaction = null) {
@@ -79,46 +72,9 @@ async function logTicketEvent(action, fields, interaction = null) {
   await sendToChannel(CONFIG.LOG_CHAN, embed, interaction?.client);
 }
 
-// --- logGmail ---
-
-async function logGmail(...args) { return; }
-
-// --- logAutomation ---
-
-async function logAutomation(...args) { return; }
-
-// --- logSecurity ---
-
-async function logSecurity(...args) { return; }
-
-// --- logIntegrity ---
-
-async function logIntegrity(issue, detail, overrideClient = null) {
-  const embed = new EmbedBuilder()
-    .setTitle('Ticket Integrity Issue')
-    .setColor(0xFF0000)
-    .addFields(
-      { name: 'Issue', value: String(issue).slice(0, 256), inline: false },
-      { name: 'Detail', value: String(detail || 'N/A').slice(0, 1024), inline: false },
-      { name: 'Timestamp', value: new Date().toISOString(), inline: true }
-    )
-    .setTimestamp();
-  await sendToChannel(CONFIG.DEBUGGING_CHANNEL_ID, embed, overrideClient);
-}
-
-// --- logSystem ---
-
-async function logSystem(...args) { return; }
-
 module.exports = {
   setClient,
   logError,
   logWarn,
-  logEvent,
-  logTicketEvent,
-  logGmail,
-  logAutomation,
-  logSecurity,
-  logIntegrity,
-  logSystem
+  logTicketEvent
 };