Explicitly default to MorphType.Stem in several places

Author: myieye

backend/FwLite/FwDataMiniLcmBridge/Api/FwDataMiniLcmApi.cs

@@ -597,7 +597,10 @@ private Entry FromLexEntry(ILexEntry entry)
                 LexemeForm = FromLcmMultiString(entry.LexemeFormOA?.Form),
                 CitationForm = FromLcmMultiString(entry.CitationForm),
                 LiteralMeaning = FromLcmMultiString(entry.LiteralMeaning),
-                MorphType = LcmHelpers.FromLcmMorphTypeId(entry.PrimaryMorphType.Id.Guid), // TODO: Decide what to do about entries with *mixed* morph types
+                // PrimaryMorphType is null if LexemeFormOA is null
+                MorphType = entry.PrimaryMorphType is null
+                    ? MorphType.Stem
+                    : LcmHelpers.FromLcmMorphTypeId(entry.PrimaryMorphType.Id.Guid), // TODO: Decide what to do about entries with *mixed* morph types
                 Senses = entry.AllSenses.Select(FromLexSense).ToList(),
                 ComplexFormTypes = ToComplexFormTypes(entry),
                 Components = ToComplexFormComponents(entry).ToList(),

backend/FwLite/LcmCrdt/Changes/CreateEntryChange.cs

@@ -43,7 +43,7 @@ public override ValueTask<Entry> NewEntity(Commit commit, IChangeContext context
             CitationForm = CitationForm ?? new MultiString(),
             LiteralMeaning = LiteralMeaning ?? new(),
             Note = Note ?? new(),
-            MorphType = MorphType ?? default
+            MorphType = MorphType ?? MiniLcm.Models.MorphType.Stem,
         });
     }
 }

backend/FwLite/MiniLcm/Models/Entry.cs

@@ -10,7 +10,7 @@ public record Entry : IObjectWithId<Entry>
     public virtual MultiString CitationForm { get; set; } = new();
 
     public virtual RichMultiString LiteralMeaning { get; set; } = new();
-    public virtual MorphType MorphType { get; set; }
+    public virtual MorphType MorphType { get; set; } = MorphType.Stem;
     public virtual List<Sense> Senses { get; set; } = [];
 
     public virtual RichMultiString Note { get; set; } = new();