fix(plugins): share BaseDbContext type across plugin ALCs

Without sharing, each plugin loads its own BaseDbContext Type in an
isolated AssemblyLoadContext, so plugin services cannot resolve the
host's BaseDbContext DI registration. Required once the host stopped
re-registering BaseDbContext in each plugin's ConfigureDbContext.

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

Author: renemadsen

eFormAPI/eFormAPI.Web/Hosting/Helpers/PluginHelper.cs

@@ -25,6 +25,7 @@ OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 
 namespace eFormAPI.Web.Hosting.Helpers;
 
+using Microting.EformAngularFrontendBase.Infrastructure.Data;
 using Microting.EformAngularFrontendBase.Infrastructure.Data.Entities;
 using Microting.EformAngularFrontendBase.Infrastructure.Data.Factories;
 using System;
@@ -317,6 +318,11 @@ private static List<IEformPlugin> LoadAllPluginsFromDisk()
                         typeof(PluginConfigurationProvider<>),
                         typeof(ConfigurationProvider),
                         typeof(DbContext),
+                        // Share Microting.EformAngularFrontendBase so the plugin's BaseDbContext
+                        // is the same Type object the host registers in DI. Without this, each
+                        // plugin loads its own copy of BaseDbContext in a separate ALC, and
+                        // plugin services cannot resolve the host's BaseDbContext registration.
+                        typeof(BaseDbContext),
                         typeof(WarningsConfiguration),
                         typeof(WarningBehavior),
                         typeof(DbContextOptionsBuilder),