feat(admin): view a user's shard footprint at /admin/users/:id

Add a "View" action beside Edit in the users table that opens a dedicated,
read-only page showing everything the uo-link shard knows about a user,
scoped to their linked game accounts: character rosters, currently-online
characters, houses (IDOC-first), and recent vendor sales.

Backend (admin-only, under the existing /users adminOnly gate):
- GET /admin/users/:id — single sanitized user (page is deep-linkable)
- GET /admin/users/:id/shard/{accounts,sales,houses,online}
- shardState: listHousesByAccounts / listOnlineByAccounts (+ model shapers)
- Extract salesForAccounts into utils/shardSales; reuse in player getSales
- Live rosters reuse the existing admin-bypass /admin/shard/* endpoints,
  so no new routes for roster/vendors/char

Frontend:
- UserDetail page reusing CharacterStats / GameAccounts / VendorSales
- GameAccounts gains a readOnly prop (drops link form + self-voice copy)
- api.admin.getUser + api.admin.userShard(id) scope; route + layout title

Tests: adminUserShard.test.js (404, account scoping, empty accounts,
salesForAccounts cap/filter). Full server suite 164 pass; client builds.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_0114TpmrNW4wNXsHq5CR72jQ

server/src/model/shardState/shardState.db.js

@@ -33,6 +33,18 @@ async function countOnline() {
 const listOnline = () =>
   query(`SELECT ${ONLINE_COLS} FROM shard_online ORDER BY name ASC`)
 
+// Online players on any of the given game accounts (admin: a user's linked
+// accounts). Empty list short-circuits so we never emit `IN ()`.
+const listOnlineByAccounts = (accounts) =>
+  accounts.length === 0
+    ? Promise.resolve([])
+    : query(
+        `SELECT ${ONLINE_COLS} FROM shard_online
+          WHERE acct IN (${accounts.map(() => '?').join(', ')})
+          ORDER BY name ASC`,
+        accounts,
+      )
+
 // Staff roles whose online presence is shown on the public Shard page. Players
 // who link an account are NOT surfaced publicly — only staff opt into visibility
 // by virtue of being staff.
@@ -89,6 +101,18 @@ async function upsertHouse(serial, fields) {
 const listIdocHouses = () =>
   query(`SELECT ${HOUSE_COLS} FROM shard_houses WHERE is_idoc = 1 ORDER BY updated_at DESC`)
 
+// Houses owned by any of the given game accounts (admin: a user's linked
+// accounts). IDOC houses first, then newest-refreshed. Empty list short-circuits.
+const listHousesByAccounts = (accounts) =>
+  accounts.length === 0
+    ? Promise.resolve([])
+    : query(
+        `SELECT ${HOUSE_COLS} FROM shard_houses
+          WHERE owner_acct IN (${accounts.map(() => '?').join(', ')})
+          ORDER BY is_idoc DESC, updated_at DESC`,
+        accounts,
+      )
+
 module.exports = {
   upsertOnline,
   removeOnline,
@@ -96,9 +120,11 @@ module.exports = {
   countOnline,
   listOnline,
   listOnlineLinked,
+  listOnlineByAccounts,
   insertEconomy,
   listEconomy,
   latestEconomy,
   upsertHouse,
   listIdocHouses,
+  listHousesByAccounts,
 }