Remove dead/stale code, dedup close+escalation paths

Dead/stale removals (grep-confirmed no consumers):
- config: drop 9 unread CONFIG keys (ROLE_TO_PING_ID, SIGNATURE,
  REMINDER_*, RENAME_LOG_CHANNEL_ID, SETTINGS_*); remove their
  ALLOWED_CONFIG_KEYS entries and the orphaned settings-site UI fields
- configSchema: delete unreachable json/string_or_json validators
- models: drop unused ticketTag field
- gmail-poll: remove unused isPollSuspended export
- utils: remove dead htmlToTextWithBlocks/decodeHtmlEntities/BLOCK_TAG_REGEX
- internalApi: remove router._allowedKeys (test it served is gone)
- discord client: drop unused GuildPresences privileged intent
- broccolini-discord: remove dormant /api 503 gate (no /api routes)

Fixes:
- context-menu ticket create now uses makeTicketName('unclaimed', ...)
  instead of the contract-violating ticket-<n> name
- drop write-only pending.userId from both close paths

Dedup / simplify:
- new services/transcript.js shares the transcript text/date/header
  builders between the button and force-close paths (had drifted)
- resolveEscalationCategoryId() replaces 3 copies of the category logic
- ticketChannelOverwrites() shares the create-permission array between
  the two interactive ticket-create paths
- finalizeBody() shares the email-cleanup tail in parseGmailMessage
- getTicketActionRow drops its never-passed options arg;
  sendTicketNotificationEmail drops its always-null subjectLine arg
- hoist invariant guild lookup out of the auto-close/unclaim loops
- drop redundant lastActivity write (and now-dead updateTicketActivity)
- /help lists all current commands and the right-click apps

handlers/commands/contextMenu.js

@@ -6,14 +6,13 @@
 const {
   ChannelType,
   EmbedBuilder,
-  MessageFlags,
-  PermissionFlagsBits
+  MessageFlags
 } = require('discord.js');
 const { mongoose } = require('../../db-connection');
 const { CONFIG } = require('../../config');
 const { getPriorityEmoji } = require('../../utils');
-const { checkTicketCreationRateLimit, getOrCreateTicketCategory } = require('../../services/tickets');
-const { getTicketActionRow } = require('../../utils/ticketComponents');
+const { checkTicketCreationRateLimit, getOrCreateTicketCategory, makeTicketName } = require('../../services/tickets');
+const { getTicketActionRow, ticketChannelOverwrites } = require('../../utils/ticketComponents');
 const { enqueueSend } = require('../../services/channelQueue');
 const { logError } = require('../../services/debugLog');
 
@@ -36,6 +35,8 @@ async function handleCreateTicketFromMessage(interaction) {
     const guild = interaction.guild;
     const lastTicket = await Ticket.findOne().sort({ ticketNumber: -1 }).select('ticketNumber').lean();
     const ticketNumber = (lastTicket?.ticketNumber || 0) + 1;
+    const creatorNickname = message.member?.displayName || message.author.username;
+    const unclaimedName = makeTicketName('unclaimed', { ticketNumber }, creatorNickname);
 
     let parentCategoryIdForTicket;
     try {
@@ -52,20 +53,10 @@ async function handleCreateTicketFromMessage(interaction) {
     let channel;
     try {
       channel = await guild.channels.create({
-        name: `ticket-${ticketNumber}`,
+        name: unclaimedName,
         type: ChannelType.GuildText,
         parent: parentCategoryIdForTicket,
-        permissionOverwrites: [
-          { id: guild.id, deny: [PermissionFlagsBits.ViewChannel] },
-          {
-            id: message.author.id,
-            allow: [PermissionFlagsBits.ViewChannel, PermissionFlagsBits.SendMessages, PermissionFlagsBits.ReadMessageHistory]
-          },
-          {
-            id: CONFIG.ROLE_ID_TO_PING,
-            allow: [PermissionFlagsBits.ViewChannel, PermissionFlagsBits.SendMessages, PermissionFlagsBits.ReadMessageHistory]
-          }
-        ]
+        permissionOverwrites: ticketChannelOverwrites(guild, message.author.id)
       });
     } catch (err) {
       console.error('guild.channels.create (context menu ticket):', err);