fix: port 7 web features and repair the endless-loading screens

Root cause behind most "stuck loading" reports: the backend changed shape
(schedules became an array, location_preferences a string) while the mobile
parser still hard-cast to Map/int. The TypeError was swallowed by a silent
catch that returned null, and screens only handled the success state, so a
parse failure rendered as a permanent spinner. Same class of bug appeared
across service lists via non-null map lookups and a total absence of
request timeouts.

Ported from prosappweb:
- in-app suggestions (POST /suggestions)
- policies/terms from GET /settings/policies
- configurable appointment length (slot_duration_minutes)
- block/unblock calendar slots (POST /services/block)
- GPS city detection on the profile (Nominatim)
- server-side professional search with haversine distance
- retry cooldown after a rejected professional application

Reliability:
- parse schedules array (day_of_week 0=Mon) and string location_preferences
- read times as wall clock, so 08:00 stays 08:00 across timezones
- carry minutes into hours in TimeOfDay.add; a minute-based step used to
  loop forever and freeze the calendar (covered by test/time_slots_test.dart)
- semver update check instead of string equality, which blocked every build
  that did not exactly match the configured version
- request timeouts across all repositories
- surface HTTP >= 400 instead of reporting failed writes as success
- error states with retry instead of an indefinite shimmer

Includes pre-existing uncommitted work from the UI redesign.

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

packages/professional_repository/lib/src/entities/professional_entity.dart

@@ -19,6 +19,7 @@ class ProfessionalEntity extends Equatable {
   final List<String> specializationsPictures;
   final Schedules schedules;
   final PaymentMethodEntity paymentMethods;
+  final int slotDurationMinutes;
 
   const ProfessionalEntity({
     required this.id,
@@ -38,6 +39,7 @@ class ProfessionalEntity extends Equatable {
     required this.specializationsPictures,
     required this.schedules,
     required this.paymentMethods,
+    this.slotDurationMinutes = 120,
   });
 
   static ProfessionalEntity fromDocument(Map<String, dynamic> doc) {
@@ -60,6 +62,8 @@ class ProfessionalEntity extends Equatable {
           List<String>.from(doc['specializations_pictures']),
       schedules: Schedules.fromDocument(doc['schedules']),
       paymentMethods: PaymentMethodEntity.fromDocument(doc['payment_methods']),
+      slotDurationMinutes:
+          (doc['slot_duration_minutes'] as num?)?.toInt() ?? 120,
     );
   }
 
@@ -81,6 +85,7 @@ class ProfessionalEntity extends Equatable {
     List<String>? specializationsPictures,
     Schedules? schedules,
     PaymentMethodEntity? paymentMethods,
+    int? slotDurationMinutes,
   }) {
     return ProfessionalEntity(
       id: id ?? this.id,
@@ -102,6 +107,7 @@ class ProfessionalEntity extends Equatable {
           specializationsPictures ?? this.specializationsPictures,
       schedules: schedules ?? this.schedules,
       paymentMethods: paymentMethods ?? this.paymentMethods,
+      slotDurationMinutes: slotDurationMinutes ?? this.slotDurationMinutes,
     );
   }
 
@@ -124,6 +130,7 @@ class ProfessionalEntity extends Equatable {
       'specializations_pictures': specializationsPictures,
       'schedules': schedules.toJson(),
       'payment_methods': paymentMethods.toDocument(),
+      'slot_duration_minutes': slotDurationMinutes,
     };
   }
 
@@ -145,7 +152,8 @@ class ProfessionalEntity extends Equatable {
         specializations,
         specializationsPictures,
         schedules,
-        paymentMethods
+        paymentMethods,
+        slotDurationMinutes,
       ];
 
   @override