[AZ-370] Refactor C17: status / point-type enums + AC RT2 update

Replaces bare strings with two enums in Common/Enums/:
  RegionStatus { Queued, Processing, Completed, Failed }
  RoutePointType { Start, End, Action, Intermediate }

Adds a Dapper EnumStringTypeHandler<T> (DataAccess/TypeHandlers/)
that round-trips enums to/from lowercase strings, registered once
at startup via DapperEnumTypeHandlers.RegisterAll(). DataAccess now
references Common (project ref) so entities can carry the enum types.

Sites converted: RegionService (5), RouteProcessingService (3),
RoutePointGraphBuilder (4), entity Status/PointType columns. Log
message and summary file format preserved via .ToLowerInvariant().

API JSON contract preserved by adding JsonStringEnumConverter with
JsonNamingPolicy.CamelCase to the http JSON options — single-word
enum members serialize to the same lowercase strings as before.

DTO renamed: Common.DTO.RegionStatus -> RegionStatusResponse to
free the RegionStatus name for the new enum (forced by the task's
explicit enum name); the renamed DTO has no public-API impact at
the JSON wire level. Stale doc references updated.

AC RT2 in _docs/00_problem/acceptance_criteria.md now lists all 4
point types (start/end/action/intermediate).

Tests: 171 / 171 unit + 5 / 5 smoke green (was 141 + 5; +30 new tests
covering type handler round-trip, set/parse, unknown-value rejection,
idempotent registration, and the AC RT2 doc check).

Co-authored-by: Cursor <cursoragent@cursor.com>

SatelliteProvider.Services.RouteManagement/RoutePointGraphBuilder.cs

@@ -1,6 +1,7 @@
 using Microsoft.Extensions.Options;
 using SatelliteProvider.Common.Configs;
 using SatelliteProvider.Common.DTO;
+using SatelliteProvider.Common.Enums;
 using SatelliteProvider.Common.Utils;
 
 namespace SatelliteProvider.Services.RouteManagement;
@@ -48,7 +49,7 @@ public class RoutePointGraphBuilder
             {
                 Latitude = current.Latitude,
                 Longitude = current.Longitude,
-                PointType = isStart ? "start" : (isEnd ? "end" : "action"),
+                PointType = isStart ? RoutePointType.Start : (isEnd ? RoutePointType.End : RoutePointType.Action),
                 SequenceNumber = sequenceNumber++,
                 SegmentIndex = segmentIndex,
                 DistanceFromPrevious = distanceFromPrevious,
@@ -74,7 +75,7 @@ public class RoutePointGraphBuilder
                 {
                     Latitude = intermediateGeo.Lat,
                     Longitude = intermediateGeo.Lon,
-                    PointType = "intermediate",
+                    PointType = RoutePointType.Intermediate,
                     SequenceNumber = sequenceNumber++,
                     SegmentIndex = segmentIndex,
                     DistanceFromPrevious = distFromPrev,

SatelliteProvider.Services.RouteManagement/RouteProcessingService.cs

@@ -3,6 +3,7 @@ using Microsoft.Extensions.Logging;
 using Microsoft.Extensions.Options;
 using SatelliteProvider.Common.Configs;
 using SatelliteProvider.Common.DTO;
+using SatelliteProvider.Common.Enums;
 using SatelliteProvider.Common.Interfaces;
 using SatelliteProvider.Common.Utils;
 using SatelliteProvider.DataAccess.Models;
@@ -146,9 +147,9 @@ public class RouteProcessingService : BackgroundService
             }
         }
 
-        var completedRegions = regions.Where(r => r.Status == "completed").ToList();
-        var failedRegions = regions.Where(r => r.Status == "failed").ToList();
-        var processingRegions = regions.Where(r => r.Status == "queued" || r.Status == "processing").ToList();
+        var completedRegions = regions.Where(r => r.Status == RegionStatus.Completed).ToList();
+        var failedRegions = regions.Where(r => r.Status == RegionStatus.Failed).ToList();
+        var processingRegions = regions.Where(r => r.Status == RegionStatus.Queued || r.Status == RegionStatus.Processing).ToList();
 
         var completedRoutePointRegions = completedRegions.Where(r => !geofenceRegionIdsList.Contains(r.Id)).ToList();
         var completedGeofenceRegions = completedRegions.Where(r => geofenceRegionIdsList.Contains(r.Id)).ToList();