feat(library): content-addressed packages and editable nesting settings

Schema v5 stores each distinct drawing package once in drawing_packages,
keyed by SHA-256; revisions point at it, so details, settings, archive and
restore revisions add no blob. The v4 drawing tables are replaced outright
(no production library existed); nest tables are untouched.

Nesting settings (cut first, priority, rotation constraints, color) become
structured record fields (DrawingLibraryRecord.Settings), returned on every
read, filterable by cutFirst, editable through the metadata endpoint and
applied by LibraryDrawingInsert. Canonical packages now leave every
record-owned field at its default, so renaming or changing settings never
changes the package hash. Saving a nest drawing to the library carries its
settings into the record.

The desktop library browser gains a Cut first column and an Edit Settings
dialog that saves notes and settings as a new revision with the same package.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

OpenNest.Server.Tests/DrawingLibraryDatabaseTests.cs

@@ -21,7 +21,7 @@ public sealed class DrawingLibraryDatabaseTests
             using (var database = new NestDatabase(factory.DatabasePath, pooling: false))
                 Assert.Empty(database.QueryDrawings(new DrawingLibraryQuery { IncludeArchived = true }).Items);
             Assert.Equal(before, NestDigest(factory.DatabasePath));
-            Assert.Equal(4L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+            Assert.Equal(5L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         }
 
         using var upgraded = new NestDatabase(factory.DatabasePath, pooling: false);
@@ -31,30 +31,56 @@ public sealed class DrawingLibraryDatabaseTests
         Assert.Equal(2, upgraded.List().Count);
     }
 
+    [Fact]
+    public void V4Upgrade_ReplacesTheDrawingTablesAndKeepsNests()
+    {
+        using var factory = new ServerFactory();
+        CreateVersion3Database(factory.DatabasePath);
+        // The v4 layout: one column set with the package blob copied into every revision.
+        Execute(factory.DatabasePath, """
+            CREATE TABLE drawings (id TEXT NOT NULL, revision INTEGER NOT NULL, name TEXT NOT NULL, package BLOB NOT NULL, PRIMARY KEY (id));
+            CREATE TABLE drawing_revisions (id TEXT NOT NULL, revision INTEGER NOT NULL, name TEXT NOT NULL, package BLOB NOT NULL);
+            INSERT INTO drawings VALUES ('00000000-0000-0000-0000-000000000001', 1, 'Old', x'504B');
+            INSERT INTO drawing_revisions SELECT * FROM drawings;
+            PRAGMA user_version=4;
+            """);
+        var before = NestDigest(factory.DatabasePath);
+
+        using var database = new NestDatabase(factory.DatabasePath, pooling: false);
+
+        Assert.Equal(5L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
+        Assert.Equal(before, NestDigest(factory.DatabasePath));
+        Assert.Empty(database.QueryDrawings(new DrawingLibraryQuery { IncludeArchived = true }).Items);
+        var record = Record();
+        database.InsertDrawing(record.Id, record, Package());
+        Assert.Equal(1L, Scalar(factory.DatabasePath, "SELECT COUNT(*) FROM drawing_packages"));
+    }
+
     [Fact]
     public void NewerSchema_IsRefused()
     {
         using var factory = new ServerFactory();
         using (new NestDatabase(factory.DatabasePath, pooling: false)) { }
-        Execute(factory.DatabasePath, "PRAGMA user_version=5");
+        Execute(factory.DatabasePath, "PRAGMA user_version=6");
 
         Assert.Throws<InvalidOperationException>(() => new NestDatabase(factory.DatabasePath, pooling: false));
     }
 
     [Fact]
-    public void FailedV4Migration_RollsBackAndCanRestart()
+    public void FailedDrawingMigration_RollsBackAndCanRestart()
     {
         using var factory = new ServerFactory();
         CreateVersion3Database(factory.DatabasePath);
         var before = NestDigest(factory.DatabasePath);
-        Execute(factory.DatabasePath, "CREATE TABLE drawing_revisions (fixture TEXT)");
+        // A table holding an index's name makes the drawing schema fail part-way through.
+        Execute(factory.DatabasePath, "CREATE TABLE ix_drawings_savedAt (fixture TEXT)");
 
         Assert.Throws<SqliteException>(() => new NestDatabase(factory.DatabasePath, pooling: false));
 
         Assert.Equal(3L, Scalar(factory.DatabasePath, "PRAGMA user_version"));
         Assert.Equal(0L, Scalar(factory.DatabasePath, "SELECT COUNT(*) FROM sqlite_master WHERE name='drawings'"));
         Assert.Equal(before, NestDigest(factory.DatabasePath));
-        Execute(factory.DatabasePath, "DROP TABLE drawing_revisions");
+        Execute(factory.DatabasePath, "DROP TABLE ix_drawings_savedAt");
         using var database = new NestDatabase(factory.DatabasePath, pooling: false);
         Assert.Equal(2, database.List().Count);
     }
@@ -176,7 +202,7 @@ public sealed class DrawingLibraryDatabaseTests
         }
     }
 
-    /// <summary>A real schema-v3 file: v4 is additive, so dropping its tables restores v3 exactly.</summary>
+    /// <summary>A real schema-v3 file: the drawing tables are additive, so dropping them restores v3 exactly.</summary>
     private static void CreateVersion3Database(string path)
     {
         using (var database = new NestDatabase(path, pooling: false))
@@ -191,7 +217,7 @@ public sealed class DrawingLibraryDatabaseTests
             database.SetDeleted(a.Id, false, 3);
         }
 
-        Execute(path, "DROP TABLE drawing_revisions; DROP TABLE drawings; PRAGMA user_version=3;");
+        Execute(path, "DROP TABLE drawing_revisions; DROP TABLE drawings; DROP TABLE drawing_packages; PRAGMA user_version=3;");
     }
 
     private static string NestDigest(string path)