Add moderation dashboard, user history & notes (Phase 6a)

Surface the Discord bot's moderation data on the admin panel: a read-only
staff dashboard over the existing mod_actions log, per-user history, staff
notes, and a new moderator role. No bot changes.

Schema
- users.role ENUM gains 'moderator' (CREATE + idempotent ALTER for existing DBs)
- new server-owned mod_notes table (staff_only/admin_only visibility)

Server
- model/moderation: read mod_actions via the shared pool (documented read-only
  cross of the bot/server ownership boundary), correlate accounts through
  user_identities (provider='discord'), flag automated actions via
  staff_user_id === bot_config.application_id; pure reshaping helpers isolated
  in moderation.pure.js so they unit-test without opening a DB pool
- model/modNotes: list/add with role-gated admin_only visibility
- admin/moderation.controller + routes under /api/v1/admin/moderation/* gated by
  requireRole('admin','moderator'); admin_only note writes require admin
- allow assigning 'moderator' in the user create/update validators

Client
- /admin/moderation overview (window tiles, type-filterable recent feed, user
  lookup) and /user/:discordId history (tabs + notes with add-note)
- RoleGate; AdminLayout filters nav and confines moderators to their section
- moderator badge + action-type/auto badges

Deferred (see plan): 6b bot event capture (joins/leaves/filter/spam), 6c appeals
(needs public accounts), 6d /internal/mod-reverse bot reversal callback.

Verified: 116 server unit tests, client build, DB-backed model smoke, full
HTTP/RBAC e2e, and a browser click-through of the dashboard.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_019rao86n5cXpwAyjdBFEshV

server/src/router/v1/admin/moderation.controller.js

@@ -0,0 +1,133 @@
+// Admin moderation dashboard (Phase 6). Read-only views over the bot's
+// mod_actions log plus server-owned staff notes. Mounted behind the
+// admin+moderator RBAC gate (see admin.routes.js). The only mutation here is
+// adding a staff note; admin_only notes are further restricted to the admin role.
+const moderation = require('../../../model/moderation/moderation.model')
+const modNotes = require('../../../model/modNotes/modNotes.model')
+const modNotesDb = require('../../../model/modNotes/modNotes.db')
+const activity = require('../../../model/activity/activity.model')
+
+const log = require('../../../utils/logger')('moderation')
+
+const VALID_TYPES = new Set(['ban', 'kick', 'mute', 'warn'])
+const MAX_LIMIT = 200
+const DEFAULT_LIMIT = 50
+
+// Parse ?limit/&offset the same way the activity log does: numeric, capped.
+function pageParams(req) {
+  const limit = Math.min(Number(req.query.limit) || DEFAULT_LIMIT, MAX_LIMIT)
+  const offset = Number(req.query.offset) || 0
+  return { limit, offset }
+}
+
+// Optional ?type filter — ignored unless it is a known action type.
+function typeParam(req) {
+  const t = req.query.type
+  return VALID_TYPES.has(t) ? t : null
+}
+
+function isAdmin(req) {
+  return req.user && req.user.role === 'admin'
+}
+
+async function getSummary(req, res) {
+  try {
+    return res.json(await moderation.summary())
+  } catch (err) {
+    log.error('summary failed', { error: err.message })
+    return res.status(500).json({ message: 'Internal Server Error' })
+  }
+}
+
+async function getRecent(req, res) {
+  try {
+    const { limit, offset } = pageParams(req)
+    return res.json(await moderation.recent({ type: typeParam(req), limit, offset }))
+  } catch (err) {
+    log.error('recent failed', { error: err.message })
+    return res.status(500).json({ message: 'Internal Server Error' })
+  }
+}
+
+async function search(req, res) {
+  try {
+    const term = (req.query.q || '').trim()
+    if (!term) return res.json([])
+    return res.json(await moderation.search(term, { limit: 20 }))
+  } catch (err) {
+    log.error('search failed', { error: err.message })
+    return res.status(500).json({ message: 'Internal Server Error' })
+  }
+}
+
+async function getUser(req, res) {
+  try {
+    const summary = await moderation.userSummary(req.params.discordId)
+    const notesCount = await modNotesDb.countForUser(req.params.discordId, {
+      includeAdminOnly: isAdmin(req),
+    })
+    return res.json({ ...summary, notes_count: notesCount })
+  } catch (err) {
+    log.error('getUser failed', { error: err.message })
+    return res.status(500).json({ message: 'Internal Server Error' })
+  }
+}
+
+async function getUserActions(req, res) {
+  try {
+    const { limit, offset } = pageParams(req)
+    return res.json(
+      await moderation.userActions(req.params.discordId, { type: typeParam(req), limit, offset }),
+    )
+  } catch (err) {
+    log.error('getUserActions failed', { error: err.message })
+    return res.status(500).json({ message: 'Internal Server Error' })
+  }
+}
+
+async function getUserNotes(req, res) {
+  try {
+    const notes = await modNotes.listForUser(req.params.discordId, {
+      includeAdminOnly: isAdmin(req),
+    })
+    return res.json(notes)
+  } catch (err) {
+    log.error('getUserNotes failed', { error: err.message })
+    return res.status(500).json({ message: 'Internal Server Error' })
+  }
+}
+
+async function addUserNote(req, res) {
+  try {
+    const visibility = req.body.visibility === 'admin_only' ? 'admin_only' : 'staff_only'
+    // admin_only notes can carry sensitive judgement calls — restrict to admins.
+    if (visibility === 'admin_only' && !isAdmin(req)) {
+      return res.status(403).json({ message: 'Only admins can add admin-only notes' })
+    }
+    const note = await modNotes.add({
+      discordUserId: req.params.discordId,
+      author: req.user,
+      body: req.body.body,
+      visibility,
+    })
+    await activity.log({
+      req,
+      action: 'moderation.note.add',
+      detail: { discordUserId: req.params.discordId, visibility },
+    })
+    return res.status(201).json(note)
+  } catch (err) {
+    log.error('addUserNote failed', { error: err.message })
+    return res.status(500).json({ message: 'Internal Server Error' })
+  }
+}
+
+module.exports = {
+  getSummary,
+  getRecent,
+  search,
+  getUser,
+  getUserActions,
+  getUserNotes,
+  addUserNote,
+}