parity(admin): D17 — SalesExpertProfile, AdminUser name parts, agent grid fields

Restores the sales-expert fields that were lost when a sales expert became
an AdminUser instead of a type=1 Customer row.

New SalesExpertProfile holds cityId, gramLevel, phone and nationalCode. A
separate table rather than columns on AdminUser, because these mean
something only for role = SALES_EXPERT. gramLevel is DECIMAL(14,4), matched
to Customer.goldCreditLimitGrams so the same credit limit has identical
precision on both tables. phone and nationalCode copy the reference exactly:
nullable, NOT unique, no format rule — createCustomer validates only mobile
and percent, and both fields are required:false on the reference form.
Inventing a uniqueness constraint would reject data the reference accepts.

reagent_id is deliberately NOT ported (D17). Every use of it in the
reference reads a CUSTOMER's reagent_id, which the target already models as
Customer.referredByAgentId. On a sales expert's own form it was a side
effect of the shared customers form: filling it removed that expert from
the selectable-agent list, because queryReagent filters on
whereNull('reagent_id'). The target's equivalent filters on role and active
only, so no agent can be dropped — strictly better than the reference.

AdminUser gains firstName/lastName with the same additive migration,
backfill and sync trigger as Customer, for all admins rather than only
sales experts. This closes D0 requirement 7, and every remaining
`fname: fullName, lname: ''` was fixed — six further sites across
admin-users, admin-comments, admin-documents, admin-orders and
admin-preorders.

listReagents now returns real city_id, city, gram_level, phone and ncode,
and left-joins so an expert without a profile still lists with empty cells
rather than vanishing. The two grid filters map through the relation. The
service upserts a profile on create and on a role change to SALES_EXPERT,
and the migration backfilled one for every existing expert.

ReagentCustomer.vue gains the four fields plus the city -> commission
autofill, ported verbatim including the reference's falsy test so a city
percent of 0 also falls through to the aux lookup (replicated, not fixed).

Tests: new sales-expert round trip 33/33, covering create with every field,
an edit form with each field populated separately, a byte-identical no-op
save, single-field edits, both grid filters with negative cases, the
left-join case and the referrer dropdown. «محمد علی» + «احمدی» survives
intact. Plus jest 32/32, auth-smoke 53/53, customer trigger 9/9, typecheck
clean on api and admin-panel. Migration dry-run twice in a rolled-back
transaction before applying; drift is zero.

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

apps/api/src/modules/admin-orders/admin-orders.service.ts

@@ -129,8 +129,8 @@ export class AdminOrdersService {
         id: o.customer.id,
         // Legacy split names into fname/lname; the new schema has one fullName.
         // Both are exposed so ported templates binding either keep working.
-        fname: o.customer.fullName,
-        lname: '',
+        fname: o.customer.firstName ?? o.customer.fullName,
+        lname: o.customer.lastName ?? '',
         fullName: o.customer.fullName,
         phone: o.customer.mobile,
       },