feat(settings): pool accounts are rows of Profiles; the separate Pool account section is gone

Settings → AI tools → Profiles now lists the account-pool accounts the user
may use (GET /api/me/pool-accounts) as rows of each tool's tab, with quota,
an 'in use' badge and Switch to (PUT /api/me/pool-accounts), plus an
Automatic row; an admin's pin locks them. A saved profile with the same
email as a pool account is shown once, as the pool row. Developers now see
Profiles too, with only their pool rows; Cursor gets a tab when the pool
holds a Cursor account for the user.

server/lib/account-pins.js

@@ -14,7 +14,7 @@
  * `setAccountUsers` is the Users page's Edit of one account: who runs on it.
  *
  * A user may also CHOOSE an account of their own (`account_choices`, Settings
- * → AI tools → Pool account, `/api/me/pool-accounts`): `preferredFor` — the
+ * → AI tools → Profiles, `/api/me/pool-accounts`): `preferredFor` — the
  * balancers' question — answers the admin's pin first, then that choice. A
  * choice is only ever among the accounts the user's group may use
  * (pool-groups.js `allowed`), checked when it is made and again at every
@@ -109,7 +109,7 @@ function setChoice(userId, tool, account) {
 }
 
 /**
- * What Settings → AI tools → Pool account shows `userId`: per tool with at
+ * What Settings → AI tools → Profiles shows `userId`: per tool with at
  * least one account they may use, those accounts (never a token), the admin's
  * pin and their own choice.
  */