fix: writer/reader correctness and determinism issues

- merge: cloneTable keeps relationships; skip-tables applies to new schemas
- diff: detect schema description/owner changes
- prisma: reader no longer turns relation fields into columns, enum
  detection via declared names; writer type mapping is ordered
- typeorm writer: keep explicit SQL types that cannot be inferred
- drizzle: enum columns call the enum constant; reader resolves them
- mysql/mssql/sqlite writers: honour OutputPath, deterministic column
  and constraint order; mssql live execute covers full schema
- template: ToYAML recovers from panics; Merge nil-pointer loop
- regenerate drizzle fixtures

pkg/diff/types.go

@@ -18,11 +18,12 @@ type SchemaDiff struct {
 
 // SchemaChange represents changes within a schema
 type SchemaChange struct {
-	Name      string        `json:"name"`
-	Tables    *TableDiff    `json:"tables,omitempty"`
-	Views     *ViewDiff     `json:"views,omitempty"`
-	Sequences *SequenceDiff `json:"sequences,omitempty"`
-	Scripts   *ScriptDiff   `json:"scripts,omitempty"`
+	Name      string         `json:"name"`
+	Changes   map[string]any `json:"changes,omitempty"` // Schema attributes that differ (description, owner), keyed by field name
+	Tables    *TableDiff     `json:"tables,omitempty"`
+	Views     *ViewDiff      `json:"views,omitempty"`
+	Sequences *SequenceDiff  `json:"sequences,omitempty"`
+	Scripts   *ScriptDiff    `json:"scripts,omitempty"`
 }
 
 // TableDiff represents differences in tables