Add Discord bot (moderation, filters, scheduling, roles, invites, site integration)

Standalone bot/ service (its own package.json/Dockerfile) managed entirely
through a new admin-only Discord Bot panel — token stored encrypted in the
DB and pushed to the bot process in-memory, never an env var. Built in
phases, each independently verified against a live Discord guild:

- Bot skeleton: gateway connection, internal shared-secret API, self-heals
  on its own restart by pulling config from the site
- Moderation core: /ban /kick /mute /warn /warnings + mod-log channel
- Word/invite/spam filtering with leetspeak-resistant normalization and a
  staff role/channel allowlist
- Scheduled messages: recurring (cron) and one-off channel posts
- Role assignment: button role menus, auto-role on join, temp roles,
  bulk role ops
- Auto-rotating primary invite with an audit log
- Site integration: news-publish -> Discord announce webhook, manual
  /announce, read-only /wiki search

Also fixes a pre-existing bug in both DB pools (server + bot): the mariadb
driver defaulted to timezone 'local', silently mis-serializing bound Date
params by the host's local offset instead of the DB's UTC session.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

bot/src/utils/duration.js

@@ -0,0 +1,16 @@
+// Parses simple duration strings ("30s", "10m", "2h", "1d") to milliseconds.
+// Returns null for anything unparseable. Discord's own timeout API caps at 28
+// days — callers should clamp to MAX_TIMEOUT_MS rather than trust user input.
+const UNIT_MS = { s: 1000, m: 60_000, h: 3_600_000, d: 86_400_000 }
+
+const MAX_TIMEOUT_MS = 28 * 86_400_000
+
+function parseDuration(input) {
+  if (!input) return null
+  const match = /^(\d+)\s*(s|m|h|d)$/i.exec(input.trim())
+  if (!match) return null
+  const [, amount, unit] = match
+  return Number(amount) * UNIT_MS[unit.toLowerCase()]
+}
+
+module.exports = { parseDuration, MAX_TIMEOUT_MS }

bot/src/utils/logger.js

@@ -0,0 +1,97 @@
+// Dual-transport logger: writes to the console AND to a log file.
+// Levels: error | warn | info | debug.
+//   LOG_LEVEL       console verbosity   (default info)
+//   FILE_LOG_LEVEL  file verbosity      (default debug — keep a full record on disk)
+//   LOG_TO_FILE     enable file logging (default true)
+//   LOG_DIR         log directory       (default <bot>/logs)
+//   LOG_FILE        log file name       (default bot.log)
+//
+// Copied from server/src/utils/logger.js rather than shared — the bot is an
+// independently deployable process with its own package.json/Dockerfile.
+const fs = require('fs')
+const path = require('path')
+
+const LEVELS = { error: 0, warn: 1, info: 2, debug: 3 }
+
+const consoleThreshold = LEVELS[(process.env.LOG_LEVEL || 'info').toLowerCase()] ?? LEVELS.info
+const fileThreshold = LEVELS[(process.env.FILE_LOG_LEVEL || 'debug').toLowerCase()] ?? LEVELS.debug
+
+// Color only on an interactive TTY — never in files or Docker logs.
+const useColor = Boolean(process.stdout.isTTY) && process.env.NO_COLOR == null
+const COLOR = { error: '\x1b[31m', warn: '\x1b[33m', info: '\x1b[36m', debug: '\x1b[90m' }
+const RESET = '\x1b[0m'
+
+// ── File transport ────────────────────────────────────────────────────
+const fileEnabled = (process.env.LOG_TO_FILE || 'true').toLowerCase() !== 'false'
+let fileStream = null
+let logFilePath = null
+
+if (fileEnabled) {
+  try {
+    const dir = process.env.LOG_DIR || path.join(__dirname, '..', '..', 'logs')
+    fs.mkdirSync(dir, { recursive: true })
+    logFilePath = path.join(dir, process.env.LOG_FILE || 'bot.log')
+    fileStream = fs.createWriteStream(logFilePath, { flags: 'a' })
+    fileStream.on('error', (err) => {
+      process.stderr.write(`[logger] file logging disabled: ${err.message}\n`)
+      fileStream = null
+    })
+  } catch (err) {
+    process.stderr.write(`[logger] could not open log file: ${err.message}\n`)
+    fileStream = null
+  }
+}
+
+function fmt(meta) {
+  if (meta == null) return ''
+  if (typeof meta === 'string') return meta
+  if (meta instanceof Error) return JSON.stringify({ message: meta.message, stack: meta.stack })
+  try {
+    return JSON.stringify(meta)
+  } catch {
+    return String(meta)
+  }
+}
+
+function emit(level, tag, msg, meta) {
+  const levelNum = LEVELS[level]
+  if (levelNum === undefined) return
+
+  const ts = new Date().toISOString()
+  const lvl = level.toUpperCase().padEnd(5)
+  const label = tag ? ` [${tag}]` : ''
+  const metaStr = meta === undefined ? '' : ` ${fmt(meta)}`
+  const plain = `${ts} ${lvl}${label} ${msg}${metaStr}`
+
+  // Console transport
+  if (levelNum <= consoleThreshold) {
+    const line = useColor ? `${COLOR[level] || ''}${plain}${RESET}` : plain
+    const stream = level === 'error' || level === 'warn' ? process.stderr : process.stdout
+    stream.write(`${line}\n`)
+  }
+
+  // File transport (plain text, no color)
+  if (fileStream && levelNum <= fileThreshold) {
+    fileStream.write(`${plain}\n`)
+  }
+}
+
+function createLogger(tag) {
+  return {
+    error: (msg, meta) => emit('error', tag, msg, meta),
+    warn: (msg, meta) => emit('warn', tag, msg, meta),
+    info: (msg, meta) => emit('info', tag, msg, meta),
+    debug: (msg, meta) => emit('debug', tag, msg, meta),
+  }
+}
+
+// Flush and close the file stream (called on graceful shutdown).
+createLogger.close = () =>
+  new Promise((resolve) => {
+    if (fileStream) fileStream.end(resolve)
+    else resolve()
+  })
+
+createLogger.emit = emit
+createLogger.logFilePath = logFilePath
+module.exports = createLogger