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/chat/chat_screen.dart

@@ -110,7 +110,7 @@ class _ChatScreenState extends State<ChatScreen> {
                               ),
                             ),
                             subtitle: widget.service.userId ==
-                                    ApiUserRepository.currentUserId ?? ''
+                                    (ApiUserRepository.currentUserId ?? '')
                                 ? GeneralReputation(
                                     userId: widget.service.professionalId,
                                     builder: (context, reputation) {
@@ -339,7 +339,7 @@ class _ChatScreenState extends State<ChatScreen> {
   List<Widget> _messagesList(List<MessageEntity> messages) {
     return messages
         .map(
-          (e) => e.ownerId != ApiUserRepository.currentUserId ?? ''
+          (e) => e.ownerId != (ApiUserRepository.currentUserId ?? '')
               ? ListTile(
                   title: Column(
                     mainAxisAlignment: MainAxisAlignment.start,