feat(schema-manager): Add Schema Management module and expose it in public API; update README to mark Phase 3 complete and move priorities to Phase 4

ts/index.ts

@@ -14,6 +14,7 @@ export * from './domain/logging/index.js';
 export * from './domain/bulk/index.js';
 export * from './domain/kv/index.js';
 export * from './domain/transactions/index.js';
+export * from './domain/schema/index.js';
 
 // Re-export commonly used items for convenience
 export {
@@ -172,3 +173,23 @@ export {
   type Savepoint,
   type TransactionCallbacks,
 } from './domain/transactions/index.js';
+
+export {
+  // Schema
+  SchemaManager,
+  createSchemaManager,
+  type FieldType,
+  type FieldDefinition,
+  type IndexSettings,
+  type IndexMapping,
+  type IndexSchema,
+  type SchemaMigration,
+  type MigrationStatus,
+  type MigrationHistoryEntry,
+  type SchemaManagerConfig,
+  type SchemaValidationResult,
+  type SchemaDiff,
+  type IndexTemplate,
+  type ComponentTemplate,
+  type SchemaManagerStats,
+} from './domain/schema/index.js';