fix: safe parsing of Prisma Decimal fields to prevent data loss on save

Prisma serializes Decimal fields (rate, latitude, longitude) as JSON
strings, causing 'as num?' casts to throw in fromDocument(). The catch
block in getProfessional() then returned an empty Profesional, so saving
overwrote all existing data with empty strings.

Also added try-catch in all patch API calls to surface errors to user
instead of silently failing with a stuck loading button.

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

lib/models/profesional.dart

@@ -134,14 +134,16 @@ class Profesional {
       address: (doc['address'] as String?) ?? '',
       aditionalAddress: (doc['additional_address'] as String?) ?? '',
       profession: (doc['profession'] as String?) ?? '',
-      ratePreferences: (doc['rate_preferences'] as bool?) ?? false,
-      rate: (doc['rate'] as num?)?.toString() ?? '',
+      ratePreferences: doc['rate_preferences'] is bool
+          ? doc['rate_preferences'] as bool
+          : doc['rate_preferences'] == 'true',
+      rate: doc['rate']?.toString() ?? '',
       locationPreferences: locationPrefsFromValue(doc['location_preferences']),
       bannerPicture: (doc['banner_picture'] as String?) ?? '',
       identificationPicture: (doc['identification_picture'] as String?) ?? '',
       certificatePicture: (doc['certificate_picture'] as String?) ?? '',
-      latitude: (doc['latitude'] as num?)?.toDouble() ?? 0.0,
-      longitude: (doc['longitude'] as num?)?.toDouble() ?? 0.0,
+      latitude: double.tryParse(doc['latitude']?.toString() ?? '') ?? 0.0,
+      longitude: double.tryParse(doc['longitude']?.toString() ?? '') ?? 0.0,
       specializations: specs,
       specializationsPictures: specPics,
       schedules: parsedSchedules,