feat(admin): normalize Persian/Arabic digits in every numeric field

Users typing on a Persian keyboard produced two distinct failures. Fields with
type="number" silently returned an empty string — the browser rejects Persian
digits, so the value was lost and saved as empty or zero. Text fields passed the
Persian characters straight through to the database, where a mobile stored as
۰۹۱۲… never matches 09… again. The secretary form hit the second case with no
validation at all.

Frontend:
- Adds digitsOnly() and the national-code schemas to lib/utils, plus lib/forms
  with numericField()/latinDigitsField() wrappers for React Hook Form fields.
- Converts every type="number" input to type="text" inputMode="numeric" with
  digit normalization; none remain. Fields that legitimately carry non-digits
  (sheba, landline) only get the digits translated, keeping IR and separators.
- Points the patient national-code and mobile schemas at the shared normalizing
  schemas, which accept Persian input instead of rejecting it.
- Drops two duplicate local digit converters in favour of the shared helper.

Backend:
- Adds NumericFieldNormalizerSubscriber, translating digits in whitelisted
  numeric keys of JSON request bodies under /api/v1/ before controllers run, so
  nobat724_front and clinic-pro-tauri are covered too. Translation only — no
  characters are stripped, non-string values and other keys are untouched.

Three component tests asserted on role="spinbutton" and numeric input values;
both are properties of type="number", so they were updated to match the new
text inputs.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

assets/admin/components/FreeVisitPrice.tsx

@@ -3,6 +3,7 @@ import { useQuery, useMutation, useQueryClient } from '@tanstack/react-query';
 import { toast } from 'sonner';
 import { api } from '../lib/api';
 import { formatRial, rialToToman, tomanToRial } from '../lib/utils';
+import { digitsOnly } from '../lib/utils';
 
 interface Pricing { free_visit_price_rials: number; require_visit_price: boolean }
 
@@ -62,9 +63,9 @@ export default function FreeVisitPrice({ doctorUuid }: { doctorUuid?: string })
             قیمت (تومان){required && <span style={{ color: 'var(--danger)' }}> *</span>}
           </label>
           <input
-            type="number" min={0} dir="ltr" className="input" style={{ width: 200 }}
+            type="text" inputMode="numeric" dir="ltr" className="input" style={{ width: 200 }}
             aria-invalid={!!error}
-            value={value} onChange={(e) => { setValue(e.target.value); setError(''); }}
+            value={value} onChange={(e) => { setValue(digitsOnly(e.target.value)); setError(''); }}
           />
         </div>
         {value !== '' && (