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>

lib/screens/lists/professional_pending_service_list.dart

@@ -66,6 +66,11 @@ class _ProfessionalPendingServiceListScreenState
                     _RequestCard(info: serviceState.services[index]),
               );
             }
+            if (serviceState is CreateServiceFailure) {
+              return _errorState(context, () => serviceBloc.add(
+                  LoadPendingServicesForProfessional(
+                      ApiUserRepository.currentUserId ?? '')));
+            }
             return _shimmerList();
           },
         ),
@@ -73,6 +78,37 @@ class _ProfessionalPendingServiceListScreenState
     );
   }
 
+  Widget _errorState(BuildContext context, VoidCallback onRetry) {
+    return Center(
+      child: Padding(
+        padding: const EdgeInsets.all(32),
+        child: Column(mainAxisSize: MainAxisSize.min, children: [
+          Container(
+            width: 72,
+            height: 72,
+            decoration: BoxDecoration(
+              color: context.subtle.withOpacity(0.1), shape: BoxShape.circle),
+            child:
+                Icon(Icons.error_outline, size: 36, color: context.subtle),
+          ),
+          const SizedBox(height: 16),
+          Text('No se pudo cargar la información',
+              style: TextStyle(
+                  fontSize: 16,
+                  fontWeight: FontWeight.w700,
+                  color: context.muted)),
+          const SizedBox(height: 6),
+          Text('Revisa tu conexión e inténtalo de nuevo.',
+              textAlign: TextAlign.center,
+              style: TextStyle(
+                  fontSize: 13, color: context.subtle, height: 1.5)),
+          const SizedBox(height: 16),
+          OutlinedButton(onPressed: onRetry, child: const Text('Reintentar')),
+        ]),
+      ),
+    );
+  }
+
   Widget _emptyState(BuildContext context) {
     return Center(
       child: Padding(